Numbers 133. Report of Major General David B. Birney, U. S. Army, commanding First Division of, and Third Army Corps.

HDQRS. BIRNEY'S DIVISION, THIRD CORPS, August 7, 1863.

COLONEL: I have the honor to submit the following report of the movements and actions of this division from June 28 to July 3, during which time it was under my command: On the morning of June 28, the Third Corps, under my command, marched from Middletown, Md., to Frederick, at which place Major-General Sickles reported for duty and relieved me from the command of the corps. I resumed command of this division, and marched to Walkersville, on the road to Taneytown, and bivouacked beyond the town. On June 30, it remained in bivouac until 3 p. m., and I then received orders to proceed immediately to Emmitsburg. Under orders from Major-General Sickles, the command bivouacked within 1 1/2 miles of the town. On the morning of July 1, the division took position beyond Emmitsburg, toward Gettysburg, covering the road from Fairfield and Gettysburg. during the afternoon of the same day, at 2 o'clock, I was ordered by Major-General Sickles to proceed immediately to Gettysburg with my First and Second Brigades and three batteries, reporting to Major-General Howard, then engaged with the enemy. The Third Brigade, Colonel De Trobriand, was left in position at Emmitsburg, covering the road referred to and as a protection to the corps trains. My command reached Gettysburg at 5. 30 p. m., marching with enthusiasm and alacrity over the road, rendered almost impassable by mud and the passage over it of the First and Eleventh Corps through the rain. On the morning of July 2, about 9 o'clock, the Third Brigade, Colonel De Trobriand, relieved by orders of the commanding general, rejoined the division. At 7 a. m., under orders from Major-General Sickles, I relieved Geary's division, and formed a line, resting its left on the Sugar Loaf Mountain and the right thrown in a direct line toward the cemetery, connecting on the right with the Second Division of this corps. My picket line was in the Emmitsburg road, with sharpshooters some 300 yards in advance. At 12 m., believing from the constant fire of the enemy that a movement was being made toward the left, I received permission from Major-General Sickles to send 100 of Berdan's Sharpshooters, with the Third Maine Regiment as a support, and feel the enemy's right. I sent Captain J. C. Briscoe, of my staff, with the reconnaissance, which was under Colonel Berdan's command. They advanced from the peach orchard out the Millerstown road, and entered the woods in order to flank the enemy. The skirmishers of the enemy were driven in, but three column of their forces were found marching to our left. The force sent by me was driven back by overwhelming numbers, with the loss of about 60, killed and wounded. Communicating this important information to Major-General Sickles, I was ordered by that officer to change my front to meet the attack. I did this by advancing my left 500 yards, and swinging around the right so as to rest on the Emmitsburg road at he peach