Report of Col. Adrian R. Root, Ninety-fourth New York Infantry commanding First Brigade.
APRIL 27-MAY 6, 1863.--The Chancellorsville Campaign.

Monday, May 11, 1863.

Capt. W. L. KIDDER,
A. A. G., Second Division, First Army Corps.

       CAPTAIN: I have the honor to submit the following report of the part taken by my command (First Brigade, Second Division, First Army Corps) during the recent operations of the Army of the Potomac:
       Pursuant to orders from division headquarters, the First Brigade, consisting of Sixteenth Maine Volunteers, One hundred and seventh Pennsylvania Volunteers, One hundred and fourth New York Volunteers, and the Ninety-fourth New York Volunteers (consolidated with the One hundred and fifth New York Volunteers, March 20, 1863), broke camp near Fletcher ChapeI at 12 m. on Tuesday, April 28, 1863. The men were supplied with eight days' rations and 60 rounds of cartridges upon their persons. Marched via the White Oak Church road, about 8 miles in a rain-storm, and bivouacked for the night in a wood about 3 miles below the city of Fredericksburg. At daylight the following morning (Wednesday, April 29), marched to the Rappahannock River in support of Wadsworth's (First) division, which crossed the river on pontoons, took the enemy's riflepits and a number of prisoners. I massed the brigade by battalions in line, in readiness for crossing.
       Remained in this position "
en bivouac" during the remainder of the day and the following night. On Thursday, April 30, it being the "National Fast Day "as proclaimed by President Lincoln, I formed the brigade in a hollow square, and observed the occasion with suitable services, conducted by the regimental chaplains. At about 4 p.m. the enemy, having obtained an accurate range of our position, threw several shells into the division, killing and wounding a number of officers and men, the First Brigade escaping with but trifling loss of wounded. The fire from the enemy's batteries increasing in amount and accuracy, the brigade was withdrawn (by order of the division commander, General John C. Robinson) about 400 yards, to the protection of the ditches and hedges bordering the River road, where it remained under fire during the night.
       Friday, May 1.--The brigade remained in the same position, under an artillery fire. In the afternoon, the men were supplied with a ration of spirits, by order of the division commander.
       Saturday, May 2.--At 9 a.m. the brigade was relieved by a portion of the Sixth Corps, and, under the fire of the enemy's batteries, marched up the River road. Arrived at the United States Ford, a distance of about 20 miles, at 5.30 p.m., and crossed the Rappahannock River upon a pontoon bridge. Halted, stacked arms, and the men, wearied with their march, partook of needed refreshments.
       At about 7 p.m. I was ordered to move rapidly to the front, to occupy the position vacated by a portion of the Eleventh Corps, which had been defeated and driven in fragments to the rear.
       The movement to the front in the darkness through a heavy forest was quite difficult, the woods having been set on fire by the enemy's shells, and being thronged with fugitives from the disorganized Eleventh Corps. I deployed the Ninety-fourth New York Volunteers, and drove several thousand of these fugitives to the front. The heavy firing had ceased on our arrival in position, and shortly afterward the brigade was ordered to move to the right, on the Ely's Ford road, and finally took position on the right of the army at about midnight, turning an angle to the right and rear.
       While taking our position, a severe action prevailed upon our left. I threw out a line of pickets and an advanced guard, the One hundred and fourth New York Volunteers being detailed for the purpose.
       The pickets became engaged in a noisy skirmish with the enemy, and sent in several prisoners, who stated that our right would be attacked in the morning. The entire brigade passed the night in throwing up breastworks, which by daylight acquired considerable strength, and justified my belief in a successful defense against the expected assault.
       Sunday, May 3.--At daylight the battle opened on our left, and continued furiously until about noon, with desultory firing of musketry and artillery during the day. Continued to strengthen our works by details, the balance of the brigade being under arms. The pickets sent in several prisoners. During a picket skirmish a German battery stationed near my lines became panic-stricken, limbered up, and disappeared to the rear. Prisoners reported the death of General Jackson.
       Monday, May 4.--Under arms all day, and strengthened our works. Relieved the One hundred and fourth New York Volunteers (on picket duty) with the One hundred and seventh Pennsylvania Volunteers. By invitation of the corps commander (General Reynolds), I accompanied him upon a reconnaissance to the right and front of our position, developing the enemy's pickets in close proximity to our own.
       Tuesday, May 5.--Under arms, in momentary expectation of an assault. A heavy rain tell, flooding the intrenchments, drenching the men, and seriously incommoding the command. Picket firing continued.
       At midnight I received orders to evacuate our position, leaving the picket line on duty, and march to the United States Ford of the Rappahannock River. After proceeding to the rear about 1 mile, I received orders to retrace our march and hasten back to our former position, the pontoon bridge having been carried away by the flood. The brigade reoccupied its position at the front.
       Wednesday, May 6.--At 4 a.m., by orders from the division commander, called in the pickets (One hundred and seventh Pennsylvania Volunteers) and deployed them to the right and left as a rear guard. Evacuated the works; marched to the United States Ford; crossed a pontoon bridge, and continued the march about 20 miles to the neighborhood of Falmouth, Va., where I halted the brigade, in a heavy rain, and bivouacked for the night.
       Thursday, May 7.--Marched at noon in the direction of White Oak Church. Bivouacked for the night in a wood near the Fitzhugh house, and, by order of the division commander, remained until Sunday, May 10, when the brigade [moved] about half a mile to its present location.
       I take pleasure in bearing testimony to the cheerfulness and alacrity with which the officers and men of my command, without exception, executed every order, and endured the extreme discomforts incident to the recent operations.

I remain, very respectfully, your obedient servant,
Colonel, Commanding First Brigade