HEADQUARTERS COMPANY A, FIRST RHODE ISLAND LIGHT ARTILLERY,
Harper's Ferry, September 24, 1862
Brigadier General O. O. HOWARD,
GENERAL: Here with I have the honor to hand you my report of the operations of my battery in the action on the 17th instant.
I left the division on the morning of the 16th instant, by order of Major F. N. Clarke, chief of artillery of the Second Corps, and crossed the Antietam Creek by the bridge on the Williamsport Road and camped that night on Hoffman's farm. Wednesday morning, at 8 o'clock, I moved my command to the front, and was ordered by Major Kip, of General Sumner's staff, to report to General Hooker. By General Hooker's order I placed my battery in position on a knoll on the left of the road, directly in front of some burning ruins, and opened fire about 9 o'clock upon a battery directly in front of my position. At 9.30 the enemy appeared upon my right front with a large column, apparently designing to charge the battery. I was not aware of their approach until the head of the column gained the brow of a hill, about 60 yards from the right fun of the battery. The pieces were immediately oblique to the right, and a sharp fire of canister opened upon them, causing them to retire in confusion, leaving the ground covered with their dead and wounded, and abandoning one of their battle-flags, which was secured by a regiment which came up on my right after the enemy had retreated. The enemy now opened a fire upon us from a battery in front, and also from one on the right, near, the white schoolhouse. Two guns were directed to reply to the battery on the right, while the fire of the rest was directed upon the guns in front, which were silenced in about twenty minutes, and one of their caissons blown up. On my left the troops of General French were engaged with the enemy, who occupied a corn-field, in front of which was a line of fencerails. About 10.30 the enemy were re-enforced, and advanced their line to the edge of the corn-field. I at once ordered the battery to open on them with shell and case-shot, using 1 1/2 seconds and 2-seconds fuses. Twice they advanced their flag to the edge of the field, but were forced to retire by the rapid and destructive fire of the battery. At 11.30, finding my ammunition running low, I sent to General Sumner for orders, and at 12 m. was relieved by Company G, First Rhode Island Light Artillery. I then withdrew my command to the ground occupied the night before, and at once refilled my ammunition-chests.
During the greater portion of the time I was engaged, the battery was without support, and exposed on its right flank to an enfilading fire from the rebel infantry. I report having expended 83 rounds of canister, 68 rounds of solid shot, 427 rounds shell, and 454 rounds of case shot-1,050 rounds in all. With the exception of the shots fired at the battery on my right, which was hid by a ridge, every shot was fired at a visible enemy, the guns pointed with care, and the accuracy of aim and length of fuse noticed. I report 4 killed and 15 wounded, a list of whom is annexed. Six horses were killed and 4 wounded. Three single sets of harness were lost by the horses getting among the burning timbers of the houses in rear of the battery.
The men of my command behaved nobly, and by their bravery and coolness prevented the loss of the guns. I would especially call your attention to Lieuts. Jefferey Hayard and Charles F. Mason, who displayed great coolness during the engagement, and handled their guns with excellent effect.
Since the battle I have exchanged my Parrott guns for a new battery of 3-inch ordnance pieces, and now report the command as ready for any duty for which you many desire to use the battery.
I have the honor to remain, general, very respectfully, your obedient servant,
J. A. TOMPKINS,
Captain First Rhode Island Light Art., Commanding Company A.
Source: OFFICIAL RECORDS: Series 1, Vol 19, Part 1 (Antietam - Serial 27) , Pages 308 - 309