|Daybreak: D'Aquin's Battery position just north of the Alfred|
Gen. E.A. Carman
War Dept., Washington, D.C.
I beg to acknowledge receipt of your letter of the 20th. Ulto. in which you desire me to give such information as I possess of the Louisiana Guard Battery in the field of Sharpsburg Sept 17 1862. 
With pleasure I comply with your request and will begin by stating that at daybreak on that day the battery was on the east side of a narrow woods, the Dunker Church being about 150 yds south east from where we were.
|6:00 Hours: Battery south of Nicodemus Heights.|
We remained in this position until our ammunition was exhausted when we moved towards the Confederate right a distance not extending 1/2 of a mile, where we replenished our ammunition chest. 
While thus engaged we were called upon by Genl J.E.B. Stuart for a howitzer which was at once rushed forward and from which Canister was fired upon an advancing Federal force.
|7:30 to before 10:30: Battery south of the Cox Farmstead.|
We remained here about an hour and when returning from it observed a 3 inch parrot gun that was so jambed between trees that it doubtless required more time for it extrication than those in command could give to it. We succeeded in removing it with its limber chest containing, I think, 25 rounds of ammunition. I remember the howitzer incident above mentioned very clearly as I had charge of it and also that the Parrott gun as I helped to remove it & it was placed in my charge.
|10:30 to 16:20 Hours: As Confederate left stabilizes, the|
battery takes up a north/south position on high
ground south of Nicodemus Heights.
The following day was given to putting our affairs in order, resting & sleeping until the time for moving toward the Potomac arrived, which river we crossed about day light on the 19th.
The Battery had four iron guns (2 rifled & 2 howitzers) made in Richmond Va. Our Captain was Edgar D’Aquin, a native of New Orleans.
Trusting the above map be of some aid to your in the object you desire be accomplished.
I am Yours very truly, Jno H. O’Connor
New Orleans July 5 1899
Gen E. A Carman War Dept
Yours of the 24th ulto enclosing a map of the Sharpsburg has been received.
|16:20 Hours: "about 4 p.m. ... we moved in a S.E. direction|
direction and reached a commanding position from
which we opened fire upon a moving force of infantry."
In referring to the points of the Compass in my former letter I was guided in so doing by a sketch of the battlefield in my possession.
Jno H. O’Connor
Source: Antietam Studies, Record Group 92, National Archives.
 The Louisiana Guard was "originally organized at New Orleans as the Louisiana Guard, Company B of the First Louisiana Infantry, but was made an independent artillery battery during the Winter of 1861. It's first Captain was Louis E. D'Aquin. After duty in the Department of Norfolk in early 1862, It served through the War with the Army of Northern Virgina, surrendering at Appomattox with 17 men present. ... The battery was attached to Hays Brigade on the [Maryland] Campaign, and served on the northern part of the battlefield at Sharpsburg, along Hauser's Ridge." Brian Downey's Antietam on the Web under Louisiana Guards.
 Ezra Carman's commentary describes the movement of the battery in some detail: "When Sedgwick's lines began to break, Poague's, Raine's, Brockenbrough's and D'Aquin's batteries started northerly along the Hauser ridge and kept up an advancing fire from all favoring points,all the time under a severe fire from the Union guns, but all the time advancing and firing. As these batteries continued moving to the left the guns were mixed up, D'Aquin's being generally in the lead. Some were halted in the Nicodemus cornfield, the highest point on the ridge, and opened fire upon the 59th New York, 15th Massachusetts and detachments of other regiments that had halted near the Nicodemus place, but one battery, supported by the 13th Virginia, moving between the woods and the cornfield, came to a knoll on the flank of the 1st Minnesota and about 260 yards from it, where it had an enfilading fire upon its line." Ezra A. Carman, The Maryland Campaign of September 1862, Vol. II: Antietam. Thomas G. Clemens, ed. (California: Savas Beatie, 2012), p. 218.
 The battery carried 1 10 pounder Parrott and 2 three inch Ordnance Rifles. Brian Downey's Antietam on the Web under Louisiana Guards.
 This was Irwin and Brooks Brigades of William Smith's Division, VI Corps. Ezra Carman noted this engagement: "J .R. Johnson's Virginia battery, which had fallen back with Trimble's Brigade, early in the morning, returned to the field about 2 p.m. and took position 300 yards to the right of and in advance of Reel's barn, a cornfield in its immediate front. It relieved Fry's Battery of H.P. Jones' battalion and immediately became severely engaged with Union artillery and poured an incessant and annoying fire upon Irwin's and Brooks brigades and upon Richardson's division, all efforts to silence it were unavailing. For some time Johnson was alone but was afterwards joined by D'Aquin's battery, which took position on his right. Both batteries were engaged until dark, with very little infantry for support. The batteries were on a point of a hill, the grass was burning around them, and when the engagement became very hot the caissons were moved to the foot of the hill to the left, near several haystacks. They retired at 8 o'clock." Ezra A. Carman, The Maryland Campaign of September 1862, Vol. II: Antietam. Thomas G. Clemens, ed. (California: Savas Beatie, 2012), pp. 339, 341.
 Col. Stapleton Crutchfield's OR of April 16, 1863 records that Captain D'Aquin's battery "captured one 10-pounder Parrott, which they brought off."
The "capture" of the Parrott is mentioned in another account: "In the battle of the 17th the battery was supported by Captain McClellan's sharpshooters. The boys could see the whites of the enemy's eyes. There was a bold charge; but it was a brave repulse. In the afternoon the company, by a proceeding not set down in the programme, captured a 10-pounder Parrott gun, afterward known as the 'D'Aquin's gun.' Brave D'Aquin was fated not to own that gun long. His hand fell as he touched his gun for the last time hard by the Rappahannock." Confederate Military History, a Library of Confederate State Military History: Volume 10.1, Louisiana. Clement Anselm Evans, ed., (Atlanta, 1899), page 244. (August, 1899). Retrieved May 10, 2013 from the Perseus Digital Library, Tufts University. Text provided by Perseus Digital Library, with funding from Tufts University. Original version available for viewing and download at http://www.perseus.tufts.edu/hopper/.
The identification of the "captured" Parrott is a mystery. D'Aquin's battery was located at all times west of the Hagerstown Pike. At 4:20, the battery was positioned 150 yards west of the Pike, south of the Dunkard Church, and opposite the intersection of the Piper Farm lane and the Pike (see Cope / Carman 16:20 hours map). The gun must have been a Confederate piece since no Union artillery was ever positioned in that location.
 Ezra Carman comments on this instance: "The greater part of Jackson's artillery did not enter the West Woods, but was in the open ground west of them, near the A. Poffenberger barn, but Poague's, Brockenbrough's and D'Aquin's batteries followed the infantry and took position, Poague's on Grigsby's line, Brockenbrough's in front of Starke's Brigade and D'Aquin's near Brockenbrough's. Before the action had fairly opened Jackson saw that D'Aquin was in a very exposed position, where, after the infantry became engaged, he could not use his guns to advantage, and ordered him out of the woods to the open ground on the west to act with Stuart's cavalry. Poague, who had done some work, at dusk of the 16th, sent back his two 10-pound Parrott guns and was given two howitzers from Rains' Battery, and, at daybreak of the 17th had three guns a few feet in advance of Grigsby's line and about 35 yards west of the Hagerstown road. Skirmishers were well out in front from D.R. Miller's on the right to beyond the Nicodemus house on the left." Ezra A. Carman, The Maryland Campaign of September 1862, Vol. II: Antietam. Thomas G. Clemens, ed. (California: Savas Beatie, 2012), p. 67.
 Captain Louis Edgar D'Aquin (1836-1862). "Captain D'Aquin was killed in action near Fredericksburg, Va, on 13 Deccember 1862, and relieved in command by Captain Charles Thompson. Capt Thompson was killed in action near Winchester, Va, on 15 June 1863. By Gettysburg the battery was under the command of Capt. Charles A. Green." Brian Downey's Antietam on the Web under D'Aquin; U.S. Census for Mobile, Alabama, 1850.
 John H. O'Connor mustered in to the First Louisiana Infantry (Nelligan's), Company B as a private on April 28, 1861 for one year service. From the record: "This regiment was detached and assigned to duty as an Independent Field Artillery Company by Special Order 272, Headquarters, Richmond, Va., dated July 25, 1861 and subsequently became Capt. Green's Company (Louisiana Guard Artillery)." Record Group 109, NARA M320. Compiled service records of Confederate soldiers from Louisiana units, labeled with each soldier's name, rank, and unit, with links to revealing documents about each soldier.
 Map not found.
 This is the Cox Farmstead located on Taylor's Landing Road which is now Mondale Road. See 10:30 map above.