Numbers 156. Report of Colonel Thomas W. Egan, Fortieth New York Infantry.

SULPHUR SPRINGS, VA., August 1, 1863.

CAPTAIN: I have the honor to submit the following account of the part taken by the Fortieth Regiment New York Volunteers in the battle of Gettysburg, Pa.: On the morning of July 2, after a prolonged and tedious march of many days, my command, following the brigade, moved from Emmitsburg, Md., up the division, which had been pushed a head the night previous. Arriving within about 2 miles of Gettysburg, moved to the right, and formed line of battle with the brigade in a wood of oaks and among rocks, about half a mile from the Emmitsburg road, and facing toward it. Resting here a few hours, marched by the flank to the left and front across an open field about 200 yards into another woods, taking position in line of battle as before, still facing the Emmitsburg road, which was at this time held by the enemy. At this point we were subjected to an enfilading fire from the enemy's batteries, which compelled a change of position. Moving across a road leading from the Emmitsburg road to the Baltimore pike, we again formed line of battle, when I was moved, by order of Colonel de trobriand, with the rest of the brigade, marching in line of battle, about 100 yards to the left and front, to the support of a battery which was stationed near a peach orchard. Ar about 4 o'clock were relieved by a portion of the Fifth Corps, when I was ordered by Major-General Birney to move by the left flank through the woods across a field of wheat, in front of Captain Winslow's battery, to a position pointed out to me by Captain J. C. Briscoe, in a ravine bounded on the left by high hills and upon the right by a gentle ridge. The enemy had at this time partly succeeded in flanking the Second Brigade upon my right by a movement upon their left. Captain Smiths's (Fourth New York) battery was stationed upon the ridge at my right, and was in a very perilous situation. The enemy having already captured two of his pieces, he called upon me in beseeching terms to save his battery. I then moved in line of battle, with my right connecting with the Second Brigade regiments, which were on the right of the battery, under a terrific fire of the enemy's infantry, who were strongly disposed behind the natural defenses of rocks and ridges, encountering also a destructive fire from his artillery. I immediately ordered my men to charge, when with great alacrity they pushed forward at a double-quick, crossing marsh up to their knees in mud and water. The enemy fell back upon my advance, but it was attended with no particular advantage to ourselves, for their new position was very much stronger than the first. All attempts to dislodge them from the second line proving unsuccessful, and discovering that they had gained ground upon my right, which threatened a flank movement, the regiments on my right having fallen to the rear and exposed us to a cross-fire, I was compelled to fall back, rallying my men upon the ridge over which I passed.