Fort Moultrie's South-West facade

Civil War Artillery

10-inch Seacoast Mortars

A fully life-size, computer-graphic replica of a 10-inch seacoast mortar

After protracted studies conducted throughout the 1830s by three successive military boards, as well as a foreign inspection-tour — all aimed at upgrading U.S. Artillery practices — it was recommended (among other measures) that a new generation of standardized, American-cast seacoast mortars be created so as to supplant the diverse mixture of pieces scattered about in various arsenals. Prototypes for two new designs in 13- and 10-inch calibers were therefore ordered in the spring of 1839, initially “cast with their trunnions centered along the barrel rather than at the base,” and each fitted with two vents. The larger 11,500-pound version would not go into immediate production, beyond its initial 13-inch prototype and a 12-inch test-variant.

Only the smaller 5,800-pound, 10-inch model was approved that following year for purchase by the War Department, the final details for actual manufacture of ten such seacoast mortars being finalized and the first orders placed as of 1841: five to be cast at Cyrus Alger’s foundry in South Boston, Massachusetts, five more at the “West Point” foundry at Cold Spring in the Hudson Highlands, about 60 miles north of New York City. Because of the differing years between:

  • the initial approval of this project;
  • the experimentation and finalization of its production-details;
  • and the actual delivery of its first finished pieces

this generation of 10-inch seacoast mortars would become rather confusingly known by a variety of designations — being broadly referred to as both the “Model 1839” and “Pattern of 1840” in early citations (such as the U.S. Army’s Ordnance Manual published in the spring of 1841), while remaining generally classified as “10 inch iron mortars, sea coast, Model 1839” as late as the U.S. Army Regulations for 1863.

Two of three Confederate 10-inch seacoast mortars, abandoned at war’s end in April 1865 behind their palmetto-revetted epaulement outside Fort Moultrie’s buried Western Postern entrance, which lies just out of sight at lower left. (Library of Congress) Two Confederate 10-inch seacoast mortars at war’s end, April 1865

Yet for all practical purposes, this weapon had also become more commonly known as the “Model 1841” or “M.1841”, presumably because of the year in which it had actually entered into service. Lt.-Col. George Talcott of the U.S. Ordnance Department would report to Congress in late 1843 how the:

… proportions and forms of garrison and sea-coast artillery have been determined, and the regulations in force are calculated to secure their being fabricated of the proper quality …

so that between October 1, 1842 and June 30, 1843, five new 10-inch seacoast mortars had been received and paid for by his department. A “Model 1844” version would also come to be mentioned in official records shortly thereafter, although it seems as if only the bed of this latter version had been altered from the original design, not any changes made in the configuration of the iron barrel itself. James A. Polk’s presidential address to Congress on December 8, 1846, would in addition mention how still more experiments had been conducted during that past year at the Fort Monroe Arsenal “with 10-inch seacoast mortar — heavy, principally to test strength, &c., of its bed.” Specifically, Fort Monroe’s Ordnance Capt. Benjamin Huger had reported:

A heavy 10-inch mortar and bed, as arranged by the ordnance board, was received from Boston. The first object was to test the strength and convenience of the mortar bed. It was fired 24 rounds — charge of powder 10 pounds — at angles varying from 36° to 60°. The bed, as arranged, stood this test, and its parts appear sufficiently strong. Some alterations proposed may render its service more convenient. Further experiments on its range and effects are proposed.

A standard design for mortar-beds had finally emerged by the early 1850s, featuring distinctly-curved iron cheeks at the front end, which were later replaced by an angled front-plane immediately prior to the Civil War.

Third of a Confederate battery of three 10-inch seacoast mortars, at right — separated from its two companion-pieces by a traverse — located just to the west of Fort Moultrie at war’s end, late April 1865 Third of a Confederate battery of three 10-inch seacoast mortars

Eventually, a total of 33 of these 10-inch seacoast mortars would be acquired  during the antebellum era by the U.S. Artillery, for distribution among various arsenals, until hostilities between North and South erupted — and in fact, this conflict’s very opening shot would be fired by Confederate Capt. George S. James’s 10-inch seacoast mortar from beside Fort Johnson on James Island, South Carolina, soaring across Charleston Harbor through the dark rainy dawn to detonate above Fort Sumter shortly before 4:30 a.m. on April 12, 1861. As full-scale mobilization thereupon ensued, a few dozen more 10-inch seacoast mortars would be hastily ordered by both sides, plus an additional eight in a heftier M.1861 version for the Union forces — although this latter design was quickly discontinued in favor of purchases of more powerful and longer-ranged 13-inch weapons.

M.1841 Seacoast Mortars at Pensacola

These photographs, attributed to J. D. Edwards of New Orleans, show two pre-war Model 1841 10-inch seacoast mortars being installed by Florida state militiamen along the shoreline of Pensacola Bay, ca. February 1861. Doubtless, they had been commandeered from among the ordnance left behind in that harbor’s Federal installations, once its small peacetime U.S. Army contingent under First Lt. Adam J. Slemmer had felt constrained to withdraw across the water into Fort Pickens on Santa Rosa Island, at the mouth of its entrance. The most recent U.S. Army inventory for Fort Barrancas, dated at the beginning of that very same year, had officially recorded its main armament as consisting of: “Thirteen 8-inch Columbiads and howitzers, two 10-inch mortars,” etc.

Seacoast Mortars at Pensacola image1 One of Two militia cannoneers posing behind their weapon with handspikes One of Two militia cannoneers posing behind their weapon with handspikes One of Two militia cannoneers demonstrate how handspikes were to be thrust beneath the maneuvering-bolts One of Two militia cannoneers demonstrate how handspikes were to be thrust beneath the maneuvering-bolts The gunner stands directly behind the mortar two men can be seen carrying a round by its shell-hooks the pyramid of ammunition visible in the rear A seventh man holds a swab used to clean out the mortar’s bore elderly gentleman with the distinctive high cheekbones, casually leaning on the weapon’s ear-lug, may quite possibly be Col. William Henry Chase

The first photograph reproduced here shows a side-view of one of these mortars in a freshly-dug emplacement, centered atop its wooden-plank platform behind a protective earthen epaulement, whose slope can be partially glimpsed at right. Note the curved cheeks of its mortar-bed, characteristic of the pre-war model and unlike the angled cheek-fronts featured on post-1860 versions. Two militia cannoneers can be seen posing behind their weapon with handspikes, while another pair demonstrate how these implements were to be thrust beneath the maneuvering-bolts, so as to leverage the mortar into firing-alignment. The gunner stands directly behind the mortar, while — given the throngs of volunteers available in these early months before hostilities had actually commenced — two additional men can be seen carrying a round by its shell-hooks (presumably brought from the pyramid of ammunition visible in the rear). A seventh man holds a swab used to clean out a mortar’s bore, while the elderly gentleman with the distinctive high cheekbones, casually standing on the weapon’s rear transom while leaning on its ear-lug, may quite possibly be Col. William Henry Chase — a retired U.S. Army engineer and wealthy local landowner, who was in command of Pensacola’s 1,700 militiamen until relieved by Confederate Brig. Gen. Braxton Bragg on March 11, 1861.

Seacoast Mortars at Pensacola image2 Comunnications Trench One of 4 men posing with handspikes One of 4 men posing with handspikes One of 4 men posing with handspikes One of 4 men posing with handspikes gunner in his proper position at its left-rear supervising officer armed with a sword and sash Colonel Chase pyramid of shells

This second photograph shows another M.1841 10-inch seacoast mortar, likewise dug in quite near to the first emplacement, both being interconnected by a communication trench. A different crew of four volunteer cannoneers are posing around this second piece, their gunner in his proper position at its left-rear, under the supervision of an officer armed with a sword and sash. In the background, Colonel Chase can be recognized again, while the pyramid of shells is once more complete — the sample shell from the first photograph having presumably been restored at its top.

Edwards’s first photograph was published in 1911 on Page 59 of Volume 5: Forts and Artillery, of Francis Trevelyan Miller and Robert S. Lanier’s ten-volume Photographic History of the Civil War; Edwards’s second photograph is held by the State Archives of Florida, image number RC04842.


Seacoast mortars constituted the heaviest category in mid-19th Century U.S. Artillery ordnance, being considerably larger than siege mortars of this same caliber — the former designed so as to provide heavy, long-range defensive fire around a major strategic position such as a harbor or city, thus seldom ever having to be moved very far, while siege mortars were lighter versions specifically created so as to be hauled overland behind an army during offensive operations, to bombard a fortified stronghold.

Consequently, the 10-inch M.1841 seacoast mortar with its 46-inch barrel stood more than twice as tall as contemporary 10-inch siege mortars, could fire twice as far, and at 5,775 pounds weighed three times as much. Seacoast mortars furthermore featured a distinctive lug called an “ear” directly atop their barrels, so as to act as a hoisting-point over their center of gravity, for the gin or winch which would of necessity have to be employed in their transportation and positioning.

10-inch M.1841 Seacoast Mortar

Dimensions & Weights
Length of barrel 46 inches 9.87 inches Diameter of shells
Diameter of bore 10 inches 1.6 inches (avg.) Thickness, iron shell-casings
Length of bore, except chamber 25 inches 1.75 inches Fuse-hole diameter
Depth of conical-shaped chamber 10 inches 87.5 pounds Weight of empty shells
Distance, muzzle-face to trunnion top 37 inches 5 pounds Powder-charge, to fill a shell
Distance between trunnion rim-bases 27.5 inches 3 pounds Powder-charge, ordinary service
Length of each trunnion 6.5 inches 2 pounds Powder-charge, to burst the shell
Diameter of each trunnion 9 inches 5 ounces Powder-charge, to blow out the fuse
Weight of barrel 5,775 pounds    
Range with a maximum 10-pound powder charge, at a 45° angle of elevation: 4,250 yards

Given the limited pre-war production of 10-inch seacoast mortars, it is likely that only a couple, or perhaps only a few at most of these weapons were ever shipped to the main depot for the harbor defenses at the U.S. Arsenal in the City of Charleston. Official returns compiled on Fort Moultrie’s peacetime armament during the years 1859-1860 do not even list a single such heavy piece among its allotted inventory, although subsequent writings — such as Gen. Samuel Wylie Crawford’s Genesis of the Civil War or Volume 5 of Gen. Clement A. Evans’s Confederate Military History — definitively cite the presence of a “10-inch seacoast mortar” among Moultrie’s artillery. (Gen. Quincy A. Gillmore’s Engineer and Artillery Operations against the Defenses of Charleston Harbor in 1863 would furthermore state that yet another unaccounted 10-inch mortar was also present at Castle Pinckney as well.)

Although certainly never part of Moultrie’s main batteries, it is nonetheless possible that one such heavy mortar — which would have been quite difficult to maneuver out from Charleston by boat into an advance firing-position on Sullivan’s Island, during any sudden crisis — may have simply been parked in reserve in the open-air compound known as the U.S. Army Reservation behind the peacetime fort, without being included among Moultrie’s official inventory.

Transportation & Emplacement

Two Confederate 10-inch seacoast mortars at war’s end, April 1865, abandoned behind their palmetto-revetted epaulement beside Fort Moultrie’s buried Western Postern entrance, which is just out of sight at lower left. (Library of Congress) Cutaway and overhead views of a wooden mortar platform (1851 Instruction for Heavy Artillery manual)

If a lone seacoast mortar was indeed stored behind Fort Moultrie, it would likely have been stood upon its muzzle atop wooden planks, with its vent sealed and its one-ton mortar bed off to one side. To move both into a firing-position with a sling cart and assemble them into a weapon, the 1861 U.S. Army Ordnance Manual directed that:

Sea-coast mortars and their beds must be slung separately. The sling-chain is passed through the clevis of the mortar and over the axle-tree, and hooked around the pole at its junction with the axle, the pole having been raised vertically.

The three-ton barrel could then be hoisted up beneath the sling cart or into an iron-framed wagon by a large work-detail, to be slowly hauled overland behind a team of oxen or powerful horses toward a selected site.

An emplacement would meanwhile have to be prepared at this site destined to receive the weapon, being laid out in the general direction in which the mortar was to be aimed (known as its “plane of fire”), and within range of any anticipated targets. To create such a gun-position, a sheltered and firm patch of land would have to be leveled off and excavated down to a depth of about nine inches, in which to lay and tamp down thick wooden sleepers to act as the mortar-platform’s foundation. Usually, the rubble and dirt being shoveled out during this excavation would be wheeled up and simultaneously mounded, so as to help erect a protective redoubt enclosing the front end of this position, known as its epaulement.

Disabled Confederate 10-inch mortar, resting at the rear of its platform within Fort Pulaski, Georgia, April 1862; note the eye-bolts anchoring the wooden platform-planks into the sleepers buried underneath. (Library of Congress) Eye-bolts on a Confederate 10-inch seacoast mortar-platform within Fort Pulaski, Georgia, April 1862

The mortar’s square wooden platform would be completed by laying thick planks cross-wise atop these embedded sleepers, the front and rear planks being firmly affixed to its foundation with eye-bolts, so as to prevent any slippage and help retain the platform’s shape against the concussive discharges which would inevitably ensue, once firing commenced.

When the weapon itself arrived at the site, its bed would first be centered atop this platform, before the heavy barrel was carefully winched down so as to be seated on top of it, and tilted at a 45° angle. Once installed, the four-ton mortar could be slewed around on its level planking by the strength of its crew alone, using handspikes for leverage. In addition, some 400 shells would also have to be delivered and stockpiled nearby, each weighing almost 90 pounds, plus a two-ton powder supply and great deal of other equipment and materiel.

Platform with a 10-inch siege mortar resting on top, photographed in August 1865 after the war’s conclusion in Fort C. F. Smith outside of Washington, D.C. (Library of Congress)  Platform with a smaller 10-inch siege mortar resting on top, photographed in August 1865

Moreover, during the Union disembarkation and entrenchment on Morris Island, South Carolina, in the third year of the Civil War to besiege Fort Wagner at the mouth of Charleston Harbor as of mid-July 1863, the engineer Maj. Thomas B. Brooks of the New York Volunteers would complain that such regulation mortar-platforms — laid down with standard 9’ x 5” x 3.5” planks supplied by the U.S. Ordnance Department — quickly “showed evidences of failing, and required important repairs after a few hours’ firing.” Therefore, in order to provide a more durable base, Brooks had substituted triple layers of heavier square timbers and planks of yellow pine, seized from local yards. (He furthermore noted the fact that “the greater the weight of the mortar in proportion to the weight of its shell, the less the injury to the platforms.”)

Crew & Equipment

Although a large work-detail would be required to transport and install a seacoast mortar into a prepared position, only five trained artillerymen would be subsequently needed to operate the weapon itself, once it had been assembled: two cannoneer privates (designated as Numbers 1 and 2) stationed “opposite to the front manoeuvring bolts, and Nos. 3 and 4 opposite to those in the rear” of the piece, all under the direction of a single noncom known as its gunner. This crew had to be equipped with an assortment of specialized instruments and tools, beginning with four handspikes for leveraging the weapon around its platform — which were normally distributed at the four corners of the mortar-bed, two on either side of it “leaning upon the four manœvring bolts, the small ends towards the epaulment, those of the front handspikes even with the front of the cheeks.”

Union artillerymen posing around a smaller 10-inch siege mortar behind its epaulement on Morris Island, South Carolina, during the summer of 1863; note the tool-basket at far left, plus the cannoneers carrying a shell suspended from a handspike, and another pair demonstrating how rounds were to be lowered into the bore. (Library of Congress) Union artillerymen posing around a smaller 10-inch siege mortar on Morris Island, South Carolina - 1863.

Whenever idle, a wooden tompion was left inserted into the mortar’s bore, so as to prevent any grit or moisture from fouling its chamber and the tiny firing-aperture at its very bottom, known as the “vent.” This tompion would have a ring or knob at its center to draw the plug out of the bore, and from which three bags would normally hang suspended:

  • the gunner’s pouch, containing his level, gimlet, vent-punch, and chalk;
  • a tube pouch, containing “the priming-wire, friction tubes, and the lanyard, wound in St. Andrew’s cross upon its handle”;
  • and a haversack, holding fuses and a pair of sleeves.

A wicker basket would be furthermore placed between the supporting runners or “cheeks” of the mortar, to hold less-fragile accoutrements such as a quadrant; a plummet; pointing-cord; a scraper and wiper; shell-hooks; pointing-hooks; a maul or heavy hammer; as well as a corn broom.


With the mortar resting at the center of its platform, and its gunner and four cannoneers standing at attention around it, an officer would shout the opening command “Take implements!” At these words, the gunner would hasten to the front of the piece and oversee the distribution of:

  • the protective arm-sleeves and wiper to cannoneer No. 1,
  • the basket and maul to cannoneer No. 2;
  • the tube-pouch and broom to cannoneer No. 3;
  • and the haversack to cannoneer No. 4.

Opening his own instrument pouch, the gunner would thereupon employ his level “to ascertain the line of metal, which he marks with chalk,” before resuming his post at the left-rear of the mortar. And while the gunner had been thus engaged:

  • cannoneer No. 1 would place the wiper on the pounded stake behind him and (assisted by cannoneer No. 3), pull on his protective sleeves, which were usually made of serge or flannel;
  • cannoneer No. 2 would remove the tompion and place it, along with the basket and maul, a yard behind his own station, and lay “the shell-hooks on the ground between himself and the basket”;
  • cannoneer No. 3 would lay the broom on the ground behind his post, and equip himself with the tube pouch;
  • and cannoneer No. 4 would sling the haversack onto his right shoulder, so as to hang down by his left side.

All four would then remove their handspikes from the maneuvering bolts, and stand at the ready.

At the shouted order “Load!”, the gunner would once again hasten to the front of the muzzle and — mounting a wooden block — reach down into its barrel and use a scraper to clear the bore and chamber of any adhered residues, drawing them out with a spoon, then returning these implements to the basket. In the meantime, cannoneer No. 1 would lay down his handspike so as to mount “upon the right cheek and bolster” of the mortar-bed, in order to use his wiper once the gunner had finished scraping out its bore and chamber, so as to ensure that both were left completely clean. Cannoneer No. 3 (likewise without his handspike) would clear the vent with the priming-wire, sweep the platform if necessary, and resume his post.

Meanwhile, cannoneers No. 2 and 4 would have hurried off to the rear with a single handspike and the shell-hooks, to obtain a powder-filled cartridge and a loaded shell. The former consisted of a stitched bag “made of bombazine or flannel,” which was handed to No. 4 from the service-magazine while the shell-hooks were being inserted into the ears of a 90-pound shell by No. 2, so as to be suspended on the handspike between both men as they carried it back to the piece.

Arriving at their mortar’s muzzle, the shell would be rested on the ground momentarily, while No. 4 handed the cartridge up to the gunner, who would insert it into the bottom of the chamber, to be rammed home by No. 1. Immediately afterward, cannoneers 2 and 3 would mount the mortar-bed’s cheeks in order to together hoist the heavy round off the ground by its handspike and shell-hooks, while No. 4 used his wiper to quickly clean the elevated shell, before it reached the mouth. The gunner and No. 1 would then assist in guiding the shell, as it was gently lowered into the bore. Once set atop the inner chamber, the gunner would remove the handspike, toss the shell-hooks behind Position No. 2, adjust the shell so that its fuse was “in the axis of the piece,” and prepare the firing-fuse.


Union artillerymen posing around a smaller 10-inch siege mortar behind its epaulement on Morris Island, South Carolina, during the summer of 1863; note the tool-basket at far left, plus the cannoneers carrying a shell suspended from a handspike, and another pair demonstrating how rounds were to be lowered into the bore. (Library of Congress) Sketch by Alfred R. Waud, of a Union gunner using a pointing-cord to aim a small 8-inch siege mortar.

A mortar was aimed by having had a pair of tall stakes driven into the earth previously atop the crest of its epaulement, about three or four feet apart and in a straight line pointed away from the weapon’s muzzle. The pointing-cord was at that time unwound, and tied to the stake which stood furthest from the piece. Drawing this cord taut until its line grazed the second stake, the opposite end of this cord would then be extended to a shorter third stake, driven into the ground about a yard directly behind the mortar platform. A foot-long piece of wood known as a “pointing-board,” notched at its center and marked with gradients, would also have been laid cross-wise on the ground behind this third stake, so as to record any subsequent adjustments in aim.

According to the 1851 Instruction for Heavy Artillery manual: “In pointing mortars, the elevation is first given and then the direction.” Therefore, cannoneers Nos. 1 and 2 — while facing toward the epaulement — would embar their handspikes “upon the bolster, under and perpendicularly to the piece,” so as to help adjust the elevation of its barrel while the gunner held a quadrant to the left side of the mortar face and directed them in either raising or lowering it, while he fine-tuned the quoin accordingly. The amount of powder loaded into the cartridge, determined the actual range or distance which the shell was to travel upon being fired.

Once the correct elevation had been calibrated, the gunner would return the quadrant into the basket, gather the pointing-cord from where it lay coiled at the foot of the epaulement, and move behind the rear stake so as to stretch this cord tight with his left hand, while suspending the plummet from it with his right. He would then use the cord in directing all four cannoneers in shifting the mortar’s front- or rear-end to left or right with their handspikes, until the target was correctly aligned — for in the words of the manual, it was “evident that when the cord, the plummet, and the line of metal are in the same plane, the mortar is properly directed.”


Once a mortar was loaded and aimed, its gunner would visibly signal to the crew with both hands, while simultaneously shouting: “Ready!” Having issued this warning, he would hasten to coil the pointing-cord back at the base of the epaulement, then take up a vantage-point to windward of the mortar so as “to observe the effect of the [forthcoming] shot.” Cannoneers Nos. 1, 2, and 4 would meanwhile retire upon seeing his signal, to reassemble in a line four yards to the rear of their platform, facing forward with “their handspikes held erect by the right side, the right arm extended naturally.”

Union artillerymen realigning a small 10-inch siege mortar on its platform in the foreground, while a trio of heavy 13-inch seacoast mortars are being loaded and fired beyond, during the July 1864 siege of Petersburg, Virginia. (William Trego, 1892) Various mortars on their platforms during the July 1864 siege of Petersburg, Virginia

Only cannoneer No. 3 would remain beside the piece, preparing a friction tube, then inserting it into the firing-vent. Once finished hooking up to the firing-mechanism, he would take the lanyard and draw back “three paces to the rear, in prolongation of the right cheek” of the weapon, leaning away from it while holding:

… the handle of the lanyard with the right hand, the lanyard slightly stretched, the cord passing between the fingers, back of the hand up …

so as to await the final command to fire.

The officer in command would ensure that all was in readiness, then shout the actual order to “Fire!” Immediately following its deafening discharge and the dispersal of smoke, the cannoneers would resume their posts at all four corners of their mortar-bed, and begin the process of clearing the weapon so as to load once more, while the gunner waited off to one side to observe the flight and detonation of the shell. A round fired with the maximum ten pounds of powder allowable in a cartridge for a 10-inch seacoast mortar, at a 45° angle of elevation, would take 36 seconds to travel the 4,250 yards that constituted its effective range — almost two-and-a-half miles.

Mortars were often emplaced together in batteries, although it was recommended that the total concentration not exceed three or four pieces, each weapon being assigned its own individual number so as to minimize any confusion during the heat of action. To fire them off in salvoes, every mortar in a battery had to first be properly loaded and aimed, and only when all crews showed themselves to be ready, would the officer in overall command of the battery shout the general directive to: “Commence firing!” However, this particular shouted command simply meant that all gunners and cannoneers were to retire to the rear of their platforms, leaving only cannoneer Number 3 at the right-rear beside each individual piece, to pull at its lanyard when given the actual signal to fire.

This would occur when the officer shouted directly at each waiting cannoneer No. 3 in turn, giving the specific designation for each individual piece as he did so, such as: “Number 1 — fire!”, “Number 2 — fire!”, etc. Common sense dictated that downwind pieces were to be discharged first, so as not to envelope the other poised cannoneers in clouds of choking, acrid gunsmoke. After every single weapon in a battery had been discharged, the shouted order “To your posts!” would ensue, for all the crews to hasten back to their stations and begin clearing, loading, and aiming their pieces once more.

Horizontal Rule

10-inch Mortars Against Fort Sumter, April 1861

In addition to the single 10-inch seacoast mortar which had apparently been found on Moultrie’s grounds, after the evacuation of its peacetime U.S. Army garrison across the mile of open water into Fort Sumter in late December 1860, South Carolina’s authorities also managed to procure fifteen more such pieces over the ensuing three-and-a-half months before inaugurating hostilities. By the time that their concentric shelling of Sumter was set to commence in the drizzly dawn of April 12, 1861, there were 27 heavy Confederate guns and sixteen 10-inch mortars distributed around the shorelines of Charleston Harbor, the latter weapons split up among seven different batteries on:

South Carolina volunteers of the Marion Artillery, posing around their pair of older M.1819 10-inch mortars with wooden cheeks and wheels, a few days after having participated in the bombardment of Fort Sumter, April 1861. South Carolina volunteers posing around their M.1819 10-inch mortars after the bombardment of Fort Sumter, April 1861.
  • James Island (near derelict Fort Johnson) under Capt. George S. James:
    • East or “Beach” Mortar Battery: two 10-inch mortars
    • West or “Hill” Mortar Battery: two 10-inch mortars
  • at the northwestern tip of Morris Island:
    • Cummings Point Battery: three 10-inch mortars (Lts. C.R. Holmes & Nathaniel Armstrong)
    • Trapier Battery: three 10-inch mortars (Capt. J. Gadsden King)
  • and at the western end of Sullivan’s Island:
    • Mortar Battery No. 1, west of Moultrie: two 10-inch mortars (Capt. James H. Hallonquist)
    • Mortar Battery No. 2, east of Moultrie: two 10-inch mortars (Capt. William Butler)
    • Mount Pleasant Battery: two 10-inch mortars (Capt. Robert Martin)

The very opening shot of the war was fired by one of Captain James’s 10-inch mortars in the East or Beach Battery, exploding directly above Sumter so as to signal the start of a general bombardment from all guns around the harbor. By that same evening, the Federal engineer Capt. John G. Foster would be noting in his journal (written while under fire within that battered stronghold), how:

The effect of the enemy’s fire upon Fort Sumter during the day was very marked in respect to the vertical fire. This was so well directed and so well sustained, that from the seventeen [sic: sixteen] mortars engaged in firing 10-inch shells, one-half of the shells came within or exploded above the parapet of the fort, and only about ten buried themselves in the soft earth of the parade without exploding. In consequence of this precision of vertical fire, Major Anderson decided not to man the upper tier of guns ...
Modern image of a M.1819 10-inch mortar An M.1819 10-inch mortar at Fort Sumter today, possibly one used during its bombardment in 1861.

Most of the Confederate mortars employed during this bombardment were M.1841 versions, although there were some older pieces present as well, as can be seen in the woodcut here above. Based upon a contemporary photograph taken by the Charleston firm of Osborn & Durbec, during a visit to Morris Island a few days after the Union garrison’s surrender, then published many years later on Page 76 of Volume 1 of Battles and Leaders of the Civil War, it recorded the militia cannoneers with their pieces at the Trapier Battery — an emplacement described in one newspaper account as being “composed of massive beams and sand-bags,” originally intended to enclose heavy guns, before being given over to these smaller weapons.

And these Trapier mortars were clearly of the older M.1819 vintage, which had lighter-weight wooden rather than iron cheeks, and thus could feature an additional set of wheels to assist in their maneuvering and aiming. Their range was considerably less than heftier M.1841 models, yet this trio of outdated pieces nevertheless succeeded in firing 170 ten-inch shells at Sumter over the span of 34 hours, compared with 197 from the Cummings Point Battery.

Horizontal Rule

Opening Shot of the Civil War

Daguerreotype of George S. James in his pre-war U.S. Army uniform, presumably taken shortly after being promoted to First Lieutenant of the 4th Artillery on December 29, 1857. (Fort Sumter National Monument) Daguerreotype of George S. James, ca. late December 1857

The first shell actually fired, which commenced four years of hostilities, came from what was seemingly an M.1841 10-inch seacoast mortar under the command of Capt. George Sholter James. When the Confederate emissaries Col. James Chesnut, Jr., and Capt. Stephen D. Lee — after a wait which had become prolonged well into the night — at last received U.S. Maj. Robert Anderson’s final refusal to surrender Sumter, they immediately penned a note inside one of that fort’s casemates at 3:20 a.m. on April 12, 1861, advising the Federal commander that the shoreline batteries would open fire against his stronghold one hour later. Then, the delegation (which included Col. A. R. Chisholm and an ex-U.S. Congressman from Virginia, the secessionist firebrand Roger A. Pryor) withdrew from Sumter aboard a private boat rowed by six slave oarsmen.

Modern diorama featuring two M.1841 10-inch seacoast mortar models, depicting the initial shot which opening began the general bombardment of Fort Sumter at dawn on April 12, 1861. (Fort Sumter Museum, National Park Service) Diorama depicting the initial shot of the Civil War, being fired against Ft Sumter on April 12, 1861

Rather than proceed all the way back into Charleston to report on this rejection, they paused en route at Fort Johnson at about ten minutes before 4:00 a.m., where Lee went ashore and was directed in the darkness to a house occupied by Captain James. Formerly a First Lieutenant in the 4th U.S. Artillery Regiment, James had resigned his commission as of February 1, 1861, to take up service with his native state. Promoted to Captain, he had supervised the installation of a pair of twin-mortar batteries on James Island, both aimed against Sumter: an advance position known as the East or Beach Battery, another further to its rear called the West or Hill Battery.

Instructed by Lee to prepare to fire off a round once the allotted deadline had elapsed, so as to signal the start of a prearranged bombardment from all around the harbor, James instantly issued orders for his men to stand to their posts, and then accompanied Lee part way back toward the wharf. James even offered the honor of pulling the first lanyard to Pryor, whom he greatly admired; but the latter demurred, replying emotionally in a choked voice that he “could not fire the first gun of the war.”

As the boat pulled back out into the dark harbor waters, James hastened to his forward-most East Battery “situated on the front beach, midway between old Fort Johnson and the Lazaretto Point.” There he ordered both of its 10-inch mortars loaded, while standing off to the right-rear of its right-hand piece with his watch in hand, so as to ensure that the deadline was punctiliously observed. Sometime between 4:25 and 4:30 a.m., he shouted the order for Lt. Henry S. Farley to actually tug the lanyard, discharging the right-hand mortar. Captain Lee, waiting expectantly aboard the emissaries’ boat — which was lying on its oars about one-third the distance between Johnson and Sumter — would record years later:

Captain James was a skillful officer, and the firing of the shell was a success. It burst immediately over the fort, apparently about one hundred feet above.
November 1860 Sketch by Hugo Bosse Panoramic view of the concentric Confederate bombardment of Fort Sumter on April 12-13, 1861, as seen out of the southeast from behind the Trapier Battery on Morris Island, SC. (Confederate War Journal)

In this engraving above, published more than three decades afterward in the monthly Confederate War Journal Illustrated, James’s battery can be pinpointed by its arching line of fire at the extreme upper-left. The West or Hill Battery of his subordinate, Lt. Wade Hampton Gibbes, is also shown firing from a still greater distance beyond, to its immediate right. In the near-foreground at left, gunsmoke can be seen curling from the heavily-reinforced Iron Battery, while the Trapier Battery is ensconced at center — its three 10-inch mortars invisible behind their sandbagged epaulements. Note the two cannoneers emerging from the Trapier’s adjoining service-magazine at lower right, carrying a 90-pound mortar shell suspended between them on a handspike. And far across the harbor, Fort Moultrie can be glimpsed amid its own smoke-plumes at the upper right-hand side of this engraving, with the unmistakable bulk of the Moultrie House Hotel looming at extreme right.

Horizontal Rule

Dismounted Mortar, Fort Pulaski, April 1862

A Confederate 10-inch M.1844 seacoast mortar, blasted off its bed during the Union bombardment of Fort Pulaski, Georgia, April 1862. (Library of Congress) A Confederate 10-inch seacoast mortar, blasted off its bed at Fort Pulaski, Georgia, April 1862

In this evocative scene captured by the 22-year-old apprentice photographer Timothy H. O’Sullivan, a Confederate 10-inch seacoast mortar can be seen lying on its back on the muddy terreplein within recently-surrendered Fort Pulaski, on Cockspur Island near the mouth of the Savannah River, Georgia, where it had fallen after having been flung backward off its bed by the detonation of a Union shell. The force of this explosion had even left the piece’s thick iron muzzle visibly damaged, and apparently sheered off the quoin-screw from its bed as well.

Pulaski’s 360-man garrison had been subjected to 30 hours of long-range, focused shelling by three-dozen heavy Union artillery-pieces on April 10-11, 1862, a barrage originally intended to batter a breach for an amphibious assault against that strongpoint by several thousand men. However, it had soon become evident during the course of this bombardment, that while smoothbore rounds had little effect on the fort’s seven-and-a-half-foot-thick masonry walls, and the aim of Union 13-inch mortars had proven disappointingly inaccurate, the high-velocity shells being fired by five of their rifled 30-pounder Parrott guns and a pair of James guns quickly smashed such a large gap through Pulaski’s southeast corner, that its defenders had capitulated rather than wait to have its northwestern magazine — now exposed directly behind this breach — inevitably struck as well, with catastrophic consequences.

Horizontal Rule

Siege Mortars on Morris Island, Summer 1863

battery weed

A week after pushing across from Folly Island onto Morris Island, South Carolina, during a dawn assault on July 10, 1863 — yet then failing to carry the Confederate stronghold next day named Fort Wagner, which guarded this latter island’s northern tip — Union Brig. Gen. Quincy A. Gillmore reported to Washington how he had decided to establish a line of artillery batteries and gradually wear down Wagner’s defenses, by having sappers dig approach-trenches under his siege guns’ covering-fire. His initial Federal line, known as the First Parallel, featured nineteen heavy pieces in its advance position named Battery Reynolds, with a support battery of another thirteen to its left-rear known as Battery Hays, and another battery of four 10-inch siege mortars to Reynolds’ right-rear named Battery Weed.

A half-dozen more Union parallels would be added over the ensuing month, as their siege-trenches edged ever closer up the coast toward Wagner, with guns and mortars being moved up in support. By mid-August 1863, Battery Weed had been left behind as one of the rear-most positions, its five 10-inch siege mortars now manned by the 7th Connecticut Volunteer Infantry under Capt. B. F. Skinner. It is believed that it was around this particular time, that the unit was photographed by the partnership of German-born Philip Haas (a pre-war daguerrian) and his assistant Washington Peale — the artillerymen posed in the act of loading and preparing to fire their smaller 10-inch siege mortars, as can be seen in greater detail by clicking on the accompanying video.

(The negative, with reproduction number LC-DIG-cwpb-04725, is identified as “Battery Reynolds” in the Library of Congress inventory, yet Reynolds was actually the higher gun-position which can be seen rearing up a few-dozen yards farther in advance of Battery Weed, at the left-hand side of this scene.)

Horizontal Rule

10-inch Seacoast Mortars, Battery Kirby, August 1863

Battery Kirby’s two 10-inch seacoast mortars, during a lull in the summer of 1863; note how their sandbag epaulements have become disarrayed from repeated firing. (Haas & Peale) 10-inch seacoast mortar at Battery Kirby, during a lull in the summer of 1863 (Haas & Peale)

Numerous other mortar-positions had also been created in the wake of the Union army’s disembarkation and entrenchment on Morris Island, South Carolina, in anticipation of General Gillmore’s slow and measured advance up its shoreline toward Fort Wagner. The journal of his assistant engineer and aide-de-camp, Maj. Thomas B. Brooks of the New York Volunteers, noted on July 15, 1863, how the position being commenced furthest inland from the sea on that date, was far out on:

... the left wing of Battery O’Rorke, afterward called Battery Kirby. Emplacements and a bomb-proof service magazine were prepared for four 10-inch siege mortars. Only one was mounted until after the 18th instant [i.e., July 1863], when two 10-inch seacoast mortars were added; these were used against Fort Sumter in the first bombardment [initiated as of August 17, 1863].

Yet since the range of 4,550 yards to Sumter lay a good 300 yards beyond the normal capabilities of 10-inch seacoast mortars, Battery Kirby’s cannoneers (initially a detachment of the 11th Maine Volunteer Infantry under the German-born U.S. Artillery specialist, Lt. Charles Sellmer) had to compensate by resorting to firing rounds only sporadically, while using cartridges overloaded with two extra pounds of gunpowder — and even then, refraining from loosing off any salvoes until there was a noticeable tailwind to help extend their shells’ flight. Otherwise, the 11th Maine gunners would hold off firing until the wind had shifted around into a more helpful direction toward their intended target, so as to be sure of striking it.

This pair of 10-inch seacoast mortars in Battery Kirby was apparently photographed in late August 1863 by the partnership of German-born Philip Haas (a pre-war daguerrian who had enlisted two years previously — at the age of 53 — in Company A of the 1st New York Engineers, and then been employed as a photographer on General Gillmore’s staff until discharged in May 1863 for health reasons) and his assistant Washington Peale, a 38-year-old painter who was the son of James Peale, Jr., of Philadelphia, and descended from a famous family of American portraitists. The text of Haas & Peale’s albumen print published during that same era, misidentified the caliber of these guns as “8-inch Seacoast Mortars,” while even the caption for the single copy held today by the Library of Congress [reproduction number LC-DIG-ppmsca-32448] refers to them as “trench mortars” — a misapplied term, “trench mortar” being a designation which did not gain widespread currency until decades later, during the First World War, and then only to describe much smaller, portable weapons similar to Coehorn mortars.

Horizontal Rule

10-inch Seacoast Mortar, Fort Sumter, September 1863

The primary target of the pair of Battery Kirby mortars mentioned in the preceding entry, was Confederate-held Fort Sumter between Morris and James Islands, guarding the western flank of Fort Wagner. When Gillmore’s Union army had first landed and started to dig siege-works along the distant seashore of Morris Island in mid-July 1863, the garrison commander within Fort Sumter — Col. Alfred Rhett of the 1st South Carolina Artillery Regiment — had been instructed to begin distributing surplus heavy ordnance from his inventory to other Confederate strongholds around the harbor, and duly reported as early as the morning of July 17, 1863, how he was sending one 10-inch seacoast mortar and its bed, plus 296 shells, across to Sullivan’s Island aboard the steamer Chesterfield. Long-range artillery exchanges between Sumter and the rapidly-multiplying “Abolition batteries” on Morris Island commenced that very same evening, but no mortars were fired back by Sumter’s garrison until two weeks later, when Rhett recorded on July 31, 1863: “Seven 10-inch mortar shells were fired between 7 p.m. and 8:30 p.m. from mortar mounted on end of wharf on southern face.”

10-inch seacoast mortar resting on its platform amid the debris of Sumter’s ravaged compound on September 8, 1863, enveloped in dust and smoke from recent Union bombardments . A few defenders can be seen peering around cautiously from their dugout shelter beyond, closer to the hot-shot-furnace. (Library of Congress)  10-inch seacoast mortar in ravaged Fort Sumter on September 8, 1863.

After participating in several more gun-duels over the next few days, this lone mortar was brought in from its exposed position on the fort’s wharf by August 4, 1863, and repositioned on a platform within Sumter’s enclosed parade next day, followed by a second mortar which was dismounted from its Gorge and installed on an adjacent platform by August 7th. Both of these weapons were used to keep up a steady, night-long counter-fire against the expanding Union batteries on Morris Island over the next several days, whose high-explosive shelling of Sumter continued to grow in intensity. When his best remaining piece of ordnance was ordered to be removed, Rhett wrote complainingly to the Assistant Adjutant-General in Charleston on August 9, 1863:

I have the honor respectfully to protest against the dismounting and shipping of the double-banded Brooke gun, mounted on the southeast angle of the fort.
I would respectfully call the attention of the Commanding General to the fact that this is the most important position, and the gun is one of the best in the fort.
I would also respectfully state that already three 10-inch Columbiads, six 8-inch Columbiads, four 8-inch navy guns, one 42-pounder, seven 32-pounders smooth bore, two 32-pounders rifled, two 24-pounders, and five 10-inch mortars have been dismounted and shipped from this fort.

With his men now working entirely at night out of safety concerns, a third 10-inch seacoast mortar was shifted from Sumter’s Gorge face into its parade by August 11, 1863, although it would not to be employed in any firing, only apparently held in reserve.

Diorama depicting the relative positions of Cook’s camera and lone 10-inch mortar inside Sumter’s compound on September 8, 1863, superimposed over Captain Foster’s pre-war diagram of the fort. (Battlefields in Motion, Ltd.) Positioning of Cook’s camera and the lone 10-inch mortar resting inside Sumter’s compound on September 8, 1863

A concerted bombardment of the fort by various powerful Federal batteries and monitors commenced six days afterward, hundreds of shells slamming into Sumter every day over the next couple of weeks, quickly silencing its guns and beating its masonry walls into enormous mounds of rubble. Although the defenders and their few hundred slave-laborers remained safe within bomb-proof shelters and casualties proved to be relatively light, most guns along its upper tier were soon dismounted or disabled, while lower casemates gradually became buried or choked with collapsing debris. By noon of August 19, 1863, Rhett was semaphoring from his battered fort that the lone 10-inch mortar which remained active in his parade had at last been “dismounted, and bed broken and shattered,” while he furthermore recorded in his journal five days afterward: “I consider only one gun, 11-inch Dahlgren, east face, as serviceable in action.”

The amount of weaponry and ammunition being withdrawn every night from Sumter was accelerated, for fear of their falling into enemy hands, and its defensibility became so reduced that by the night of September 3-4, 1863, both the chief Confederate engineer Maj.-Gen. Jeremy F. Gilmer and Brig. Gen. Roswell S. Ripley inspected the badly-damaged fort separately, in anticipation of having to give an order to evacuate it along with Fort Wagner. When the latter stronghold was abandoned along with Morris Island three nights later, the chief-of-staff in Charleston — Gen. Thomas Jordan — felt so moved that he asked for a volunteer photographer to record Sumter’s shattered state as well, “to show to future generations what Southern troops can endure in battle.” George S. Cook and James M. Osborn offered their services and were rowed across from the city under cover of darkness on the night of September 7-8, 1863, while its darkened hulk was still being subjected to intermittent Union shell-fire.

Cook’s famous “exploding shell” photograph, which also includes the lone mortar in the right background. Inexplicably, the ramparts above it show less battle-damage than other photographs taken this same day — note the numerous guns still mounted on their barbette-carriages, and the flag fluttering from its staff atop the terreplein. (Library of Congress)  Cook’s famous “exploding shell” photograph, which also includes the lone mortar in the right background. Inexplicably, the ramparts above it show less battle-damage than other photographs taken this same day — note the numerous guns still mounted on their barbette-carriages, and the flag fluttering from its staff atop the terreplein. (Library of Congress)

Next morning, amid continual rounds of shelling, a couple of Cook’s photographs captured the lone remaining 10-inch seacoast mortar sitting forlornly on its platform near the hot-shot furnace in the eastern corner of Sumter’s ravaged compound. The mortar’s tompion was inserted and no implements or prepared ammunition can be seen anywhere near it, as the defenders were no longer able to risk firing from its exposed platform.

Horizontal Rule

Emplacing Union Mortars, Virginia, July 1864

The Union emplacements being dug to receive two 10-inch mortars near “Butler’s Crow’s Nest” in early July, 1864; note the wooden observation tower rearing above the trees at center-right. (U.S. National Archives) A “clevis & bolt” attached to a 10in mortar’s lug or ear, for hoisting it off the ground

The photograph at left shows a Federal work-detail preparing to install two 10-inch seacoast mortars near “Butler’s Crow’s Nest”, opposite Dutch Gap on the James River in Virginia, during the summer of 1864. The initial northwestward push from the fishing village of Bermuda Hundred toward the Confederate capital of Richmond in May 1864 by Maj.-Gen. Benjamin Butler’s 33,000-man “Army of the James”, had been foiled by 18,000 defenders under Gen. P.G.T. Beauregard.  Butler’s second attempt that following month to reach the vital railway-hub at Petersburg, had also ended in failure by June 9th, after which further ill-coordinated assaults by Maj.-Gens. Winfield S. Hancock and George G. Meade had endured heavy casualties, for little gain. With President Lincoln beginning his re-election campaign amid a mounting public outcry in the North against such fruitless losses, the Union armies suspended their offensive operations in favor of digging in where they had become stalled, and instituting a protracted siege of Petersburg.

As part of these entrenchments, a dispatch was directed on July 5, 1864 from Col. Henry Abbot of the 1st Connecticut Heavy Artillery Regiment, instructing Capt. Alfred Mordecai, Jr., to prepare a battery near “Butler’s Crow’s Nest” to receive a Sawyer gun and a 100-pounder Parrott.  Later that same day, Mordecai replied that two 10-inch mortars were also ready for mounting, apparently referring to these pieces pictured here above [Official Records, Series I, Vol. 40, Part III, Serial 82, pp. 23-24].

Once the ground had been cleared and a flat space leveled off, their protective epaulements would be completed by mounding up the shoveled dirt, and platforms of layered wooden planks would then be embedded firmly into the soil within these protective enclosures, so as to receive the mortar beds. The latter weighed almost a ton apiece, and once heaved onto their individual wooden platforms, each bed would be followed by its three-ton mortar barrel, which would have to be winched overhead into position with a gin and seated of the mortar-bed itself at a 45° angle. Note how the bed at the center of the picture here above is shown temporarily resting atop a sleeper, its front end tilted up off the ground so as to make it easier to raise and reposition this heavy item onto its wooden platform later on.

Horizontal Rule

Captured Mortar at Fort McAllister, Georgia, December 1864

Confederate 10-inch seacoast mortar abandoned in its deteriorated emplacement at Fort McAllister, Georgia, as photographed by Samuel A. Cooley on December 16-17, 1864. (Library of Congress) Confederate 10-inch seacoast mortar abandoned at Fort McAllister, Georgia, December 16-17, 1864

Originally an earth- and log-fortification on the southern bank of the Ogeechee River, this fort had been erected to deny passage upstream to large ocean-going Union warships, which might otherwise penetrate inland and threaten the vital railway crossing at King’s Bridge, or even Savannah itself. From an initial allotment of only four smoothbore 32-pounder guns, McAllister’s armament had been further augmented by an 8-inch Columbiad, a 42-pounder, and a 10-inch seacoast mortar by the time that a Federal ironclad, three gunboats, and a mortar-boat finally came looming out of the mist at dawn on February 1, 1863, to challenge its defenses.

Capt. Robert Martin of the Georgia Light Artillery (an officer who two years previously had directed the mortar battery at Mount Pleasant, South Carolina, during the war’s opening bombardment against Fort Sumter — see above) suddenly found himself thrust into command of McAllister’s lone 10-inch mortar, and afterwards reported how he arrived at his post:

... a few minutes after 9:00 a.m. [on February 1, 1863] and immediately opened fire on the Abolition fleet. At 10:40 a.m., my platform gave way, and I was compelled to remove the planking and fire from the second tier of boards, which stood the firing very well.

Despite admitting that his “practice was at first bad,” Martin and his crew soon became very proficient. Over the next few months, accurate long-range fire from his single mortar would prove vital in driving off several more Union naval attacks.

Inevitably, though, the 60,000-man army of Maj.-Gen. William T. Sherman appeared out of the interior of Georgia from smoldering Atlanta by late autumn 1864, bound on its infamous “March to the Sea.” Bent upon linking up with the Union supply-fleet awaiting him offshore, this Federal commander closed in on Fort McAllister from its landward side by the evening of December 12, 1864. Next afternoon, its under-strength Confederate garrison of less than 200 men was overwhelmed by an assault by three Union brigades under Brig. Gen. William B. Hazen.

McAllister’s 10-inch seacoast mortar played no part in this final battle, and was photographed by Samuel A. Cooley on December 16 or 17, 1864 — according to the excellent analysis done by Roger S. Durham — while it still sat forlornly mired in mud within its neglected emplacement. This weapon was disposed of shortly thereafter by Union soldiers of the 70th Ohio and 55th Illinois Infantry Regiments, but has been replaced in modern times by a life-size reproduction cast by South Bend Replicas (albeit mounted on an undersized siege-bed).

Horizontal Rule

Union Mortar-Battery on Morris Island, ca. March 1865

Battery Chatfield

The video-clip at right provides a brief camera-pan over a pair of Federal 10-inch seacoast mortars, still emplaced toward the war’s end at the northern tip of Morris Island, South Carolina — apparently part of the ordnance remaining in position near Battery Chatfield, and which had been used to bombard the Confederate defenders on Sullivan’s Island until their retreat in mid-February 1865. Given the tidy appearance of these weapons and their platforms, this scene must have been photographed during the spring of 1865, well after having last been involved in any live action — the picture most likely taken by Samuel A. Cooley or one of his assistants in late March or early April 1865. Note how a single five-man crew has been posed rather awkwardly around both mortars, distributed between this pair of weapons so as to help stage the scene.

Certain interesting details can nevertheless be appreciated in the close-ups shown by this video-pass: for example, each mortar’s firing-vent is snugly covered with an “apron” made out of light, pliable metal, held on by a leather cinch tightened securely around the weapon’s base, so as to prevent any moisture or grit — such as falling rain or windborne sand — from fouling this vital aperture. Handspikes for both crews are slotted neatly against the revetment at far right, still ready to be drawn out for instant use, while an empty haversack for carrying powder-cartridges from a service-magazine to the mortars also dangles from a peg. And note the stakes still pounded into the ground behind each mortar, as well as the advance stakes protruding from the crest of their epaulement beyond, having been driven into its sand for the purpose of realigning the weapon and helping to re-aim it after each successive discharge, so as to fire with accuracy repeatedly at a specific target in the distance.

Distant view of this same pair of 10-inch seacoast mortars near Battery Chatfield, at the northeastern tip of Morris Island, South Carolina, ca. March 1865. (Library of Congress) Distant view of this same pair of 10-inch seacoast mortars near Battery Chatfield

A second, more distant view of this same pair of mortars ensconced within their square epaulement near Battery Chatfield — printed on a small stereographic card attributed on its reverse-side to “Sam. A. Cooley, Photographer Tenth Army Corps, Galleries at Beaufort, Folly Island, Hilton Head, S.C. and Jacksonville, Florida” — shows the single five-man mortar crew now properly repositioned around only one piece. Note the pyramids of well-oiled 10-inch shells stacked outside of the epaulement and nearer to the camera at right, as well as the fact that three of the four onlookers are wearing overcoats — indicative of cool late-winter weather. The shadow-lines furthermore indicate that this photograph was taken toward evening, as the sun was setting in the west.

Horizontal Rule

Mortars Stockpiled in a Federal Depot, April 1865

Four 10-inch seacoast mortars, stockpiled amid dozens of iron barbette-chassis and empty shells in the Union ordnance depot on Morris Island, South Carolina, toward the war’s end; a photograph attributed to Samuel A. Cooley, taken in March or April 1865. (Library of Congress) Four 10-inch seacoast mortars, in the Union ordnance depot on Morris Island, South Carolina

The unstoppable penetration by Sherman’s huge army into the heartland of prostrate South Carolina, meant encirclement for Charleston Harbor’s exhausted Confederate defenders — who at last felt compelled to withdraw on the night of February 17, 1865, from their long-held forts: Sumter, Johnson on James Island, and Moultrie on Sullivan’s Island. Next day, the besieging Union regiments would begin moving out from their positions on Morris Island to occupy all three of these battered strong-points — as well as the silent, ghostly City of Charleston — marking an end to all organized military resistance throughout this district. Although the Confederate government would not capitulate for another couple of months, these Federal troops were able to secure full control over the entire area around Charleston, to such an extent that they even began dismantling some of their own sprawling works and encampments on Morris Island over the ensuing weeks.

This accompanying photograph from the Library of Congress, one in a series of three similar views of this depot presumably taken by Samuel A. Cooley or one of his assistants — most likely in April 1865, during the wait by reporters and Union dignitaries for the ceremonial restoration of Maj. Robert Anderson’s original Stars-and-Stripes flag above Fort Sumter — shows numerous artillery pieces, shells, and other bits of heavy equipment which had been unceremoniously gathered up and dumped amid the storage sheds in this sandy compound, presumably for redistribution around the harbor-defenses, or even shipment by sea entirely out of this theater of operations. The 10-inch mortars, once one of the most powerful long-range weapons in the U.S. Artillery’s inventory prior to the Civil War, were by now outdated relics of little appreciable military value. The 13-inch mortars had since superseded them in importance, while ordnance capable of accurately firing much heavier shells over significantly greater distances had been developed and deployed over the intervening four years of warfare.

Horizontal Rule

Discarded Confederate Mortars, Fort Johnson, April 1865

Discarded Confederate Mortar

Before having abandoned their strongpoints on James Island on the night of February 17-18, 1865, Fort Johnson’s Confederate garrison had first disabled all of its guns by chopping through their carriage-braces, reducing these wooden supports to such a weakened state that their pieces could not be safely fired, until the iron guns had been painstakingly removed from their mountings and these supports replaced. And at least three of Fort Johnson’s 10-inch seacoast mortars had likewise been temporarily incapacitated, by being left dumped on the soft sandy beach without their beds, so as to complicate the task for any Federal soldiers who might arrive and attempt to hoist and remount them.

However, since the Union besiegers possessed an abundance of superior heavy ordnance, Fort Johnson’s antiquated pieces were left ignored where they were found by the victors. The accompanying video-clip above shows a close-up view of one of these three mortars, still lying forlornly several weeks later on the shoreside, beside what remained of Fort Johnson’s old wooden wharf. This photograph has been tentatively attributed to George N. Barnard and dated “March 1865,” although the Stars-and-Stripes flying at half-staff in the background would suggest that it might have been taken in late April 1865, during the period of public mourning following the assassination of President Lincoln at Ford’s Theater in Washington, D.C.

Trio of 10-inch seacoast mortars, left abandoned beside Fort Johnson’s burnt wharf upon the evacuation of this outpost’s Confederate garrison; note the heavy sling-cart and harnessed mules at left, perhaps about to be used to retrieve these dismounted mortars. (Library of Congress)  Trio of 10-inch seacoast mortars, abandoned beside Fort Johnson

A close-up detail at right, cropped out from a second photograph attributed to Barnard and looking back northwestward along this same stretch of beachfront from near the flagpole itself, clearly shows all three of these abandoned 10-inch mortars lying on the sand. Note the sling-cart and harnessed mules in this second picture at left, possibly suggesting that an attempt was about to be made by Fort Johnson’s occupiers, to at least move these derelict pieces away from the water. Official U.S. Army reports later confirmed that the fort’s captured Confederate ordnance would remain where it had been found when this battery was seized, until Company K of the 54th Massachusetts (Colored) Infantry Regiment was ordered to James Island on July 31, 1865, to assist in disassembling this out-of-date weaponry and shipping it out for disposal elsewhere — a task which was completed two weeks afterward.

Horizontal Rule

Surviving Relics and Modern Replicas

Compared to the U.S. Army’s other categories for heavy artillery, such as 32-pounder seacoast and 24-pounder siege guns (whose pre-war inventories had numbered in the thousands), only a few dozen 10-inch seacoast mortars had ever been cast and delivered to various Eastern strongholds during the antebellum era — well under 100 in total. And by the end of the Civil War, these few weapons had been further rendered obsolete by the evolution of more powerful mortars and longer-ranged guns, so that — according to a general report on “Ordnance and Ordnance Stores” submitted to the U.S. House of Representatives in June 1868 — only nineteen “10-inch sea-coast, cast-iron” mortars still remained “in the hands of troops” (two without their requisite mortar-beds), plus another sixteen stored in diverse Federal arsenals and armories, for a total of 35 surviving serviceable weapons. (Another eighteen 10-inch seacoast mortars were also recorded in this same general inventory under “trophies,” possibly referring to older pieces which had been captured from foreign enemies during previous wars.)

When two decades afterward, the U.S. House passed a resolution during the summer of 1888 intended to create “a national military and naval museum in the city of Washington”, a search was ordered made through all Federal inventories so as to locate suitable vintage pieces for display. The Army’s Chief of Ordnance — Brig. Gen. Stephen Vincent Benét (grandfather of the future poet of this same name) — replied in writing to the Secretary of War by early December 1888, informing him that with regard to 10-inch seacoast mortars, only two of the oldest vintage models could be found among the hundreds of outdated weaponry on hand:

10-inch seacoast mortars around the base of the Soldiers and Sailors Monument in today’s Courthouse Square at Binghamton, New York. (Broome County Courthouse) 10-inch seacoast mortars around the base of the Soldiers and Sailors Monument in today’s Courthouse Square at Binghamton, New York.
  • one “10-inch sea-coast mortar, M.1841”, at the Allegheny Arsenal of Pittsburgh, Pennsylvania, and
  • another 10-inch seacoast mortar, M.1841 (with markings “R.P.P.” and “W.P.” on its trunnions), at the New York Arsenal on Governor’s Island.

That same July 4, 1888, a 49-foot granite “Soldiers and Sailors” Monument had coincidentally been unveiled in front of the Broome County Courthouse in Binghamton, New York. When that building burned down eight years afterward and construction of a larger new courthouse commenced, the monument’s volunteer committee was asked for permission to remove their memorial to the northwest corner of the square. The committee’s director — Civil War veteran Gen. Edward F. Jones — refused, and as the finishing touches were being put on the reconstructed courthouse’s dome in December 1899, the Erie Railroad delivered four 10-inch seacoast mortars which Jones had obtained from Fort Jay on Governor’s Island, to be defiantly installed at each corner of his monument — where they remain to this day. (Although identical to older-vintage M.1841 pieces, this particular quartet of mortars had actually been cast during 1861-1862 at the West Point foundry in Cold Spring, New York, as part of a rush-order for eighteen such weapons placed by the U.S. Ordnance Department during the opening months of the Civil War.)

For many years, one other lone 10-inch seacoast mortar dating from the 1840s could be viewed on display in the Watervliet Arsenal Museum, which was housed in a 19th-Century building on the grounds of a much larger U.S. Army compound on the west bank of the Hudson River just north of Albany, New York — this particular relic having originally been cast in 1842 at the West Point foundry in Cold Spring, New York. However, this museum itself was ordered shut down in October 2013, because of security concerns regarding the stream of visitors entering and circulating through this active military base — which additionally contained large manufacturing and research facilities — so that the museum’s collection of relics had to be dismantled and dispersed among other institutions.

Watervliet’s 10-inch seacoast mortar was therefore shipped out in 2014 to be given a new home at the U.S. Army Artillery Museum at Fort Sill, Oklahoma, as can be seen in the four modern photographs here above. And a modern reproduction of a 10-inch seacoast mortar made by South Bend Replicas, can be examined as well at Fort McAllister, Georgia.

Horizontal Rule