HEADQUARTERS SECOND DIVISION, SIXTH CORPS,
Camp near Sharpsburg, Md., September 30, 1862.

COLONEL: I have to report, for the information of the general commanding the corps, that my division left camp near Crampton's Pass at on the field of battle near the Antietam Creek about 10 o'clock a. m., and I was at first ordered to mass the troops on the road to Sharpsburg, ready to support the attack on the right or left, as might be required. In short time I was ordered to form my division to command the ford across the creek, and in rear of where it was then supposed our troops were engaged with the enemy.

On arriving at the designated point, I was ordered by General Sumner to form the division in rear of some batteries on our extreme right. Before the division was formed, I learned from Lieutenant-Colonel Taylor, of General Sumner's staff, that a battery on our right center was unsupported, and I ordered two regiments form the First Brigade (General Hancock's) to its support. Shortly after, on visiting the ground. I ordered the remaining regiments and two batteries forward to the threatened point; and, finding that the enemy were advancing, I ordered forward the Third Brigade (Colonel Irwin's), who, passing through the regular battery, then commanded by Lieutenant Thomas (Fourth Artillery), charged upon the enemy, and drove them gallantly until abreast the little church at the point of woods, the possession of which had been so fiercely contested.

At this point a severe flank fire from the woods was received by the Thirty-third and Seventy-seventh New York Regiments, which threw both regiments slightly into confusion. They were immediately rallied by their officers and faced by the rear rank, and ordered to lie down behind the crest of a slope facing toward the woods. The rest of the brigade was ordered to form behind a crest nearly at right angles to the other, facing to their proper front. The brigade remained in this position, subjected to a heavy artillery fire and practice from sharpshooters, for twenty-four hours, until relieved by a brigade from General Couch's division.

I refer to the report of Colonel Irwin to show with what determination this exposed position was held. I also refer particularly to the report of Major Hyde, Seventh Maine Volunteers, with reference to the gallant conduct of that regiment, acting under the orders of Colonel Irwin. These orders were not made known to me till after the regiment had moved.

I beg leave here to mention the following-named officers belonging to this brigade, whose conduct was particularly gallant under my own observation:

Colonel W. H. Irwin, commanding Third Brigade; Colonel E. von Vegesack, commanding Twentieth New York Volunteers; Lieutenant Colonel J. W. Corning, commanding Thirty-third New York Volunteers; Captain E. Martindale, commissary of subsistence, Third Brigade; Lieutenant John J. Carter, Thirty-third New York Volunteers.

As soon as the Third Brigade was established in its position, I sent back for the Second Brigade (General Brooks') to act as a support, but it had, without my knowledge or consent, been ordered away. It is not the first or second time during a battle that my command has been dispersed by orders from an officer superior in rank to the general commanding this corps, and I must assert that I have never known any