Numbers 258. Report of Major General Henry W. Slocum, U. S. Army, commanding Twelfth Army Corps.

HDQRS. TWELFTH CORPS, ARMY OF THE POTOMAC,
May 17, 1863.

GENERAL: I have the honor of submitting the following report of the operations of the troops under my command, from April 27 to the 6th instant:

In obedience to instructions from headquarters Army of the Potomac, the Twelfth Corps marched, on April 27, form its present position to a point near Hardwood Church. On the 28th, the march was continued, and the entire corps encamped at 4 p. m. near Kelly's Ford. At this point I was instructed to assume command of the Eleventh and Twelfth Corps, and to move both corps to Germanna Bridge on the following day, and, if possible, effect a crossing at once.

The Twelfth Corps commenced the march at 4 a. m. on the 29th, and was followed by the Eleventh Corps. Soon after leaving Kelly's Ford, the advance guard met a small force of the enemy's cavalry, and captured 1 captain and several privates within 4 miles of the ford.

During the entire march from the Rappahannock to the Rapidan, the advance guard, consisting of the Sixth New York Cavalry, Lieutenant-Colonel McVicar commanding, was opposed by small bodies of cavalry, but the progress of the main body was but little delayed, and several captures were made on the march. On arriving at Germanna Ford, our crossing was opposed by a body of infantry, consisting of 125 men, who were posted in a mill and behind timber, which had been collected on the opposite side of the river for the purpose of rebuilding the bridge at this place. The Second Massachusetts and Third Wisconsin Volunteers were at once marched in line of battle to the bank deed. The passage of the river was at once effected by the cavalry, followed by Generals Ruger's and Jackson's brigades, of Williams' division, and all the artillery of the corps.

While the troops were fording the river, the pioneers of the First Division were engaged in the construction of a bridge. This work, under the supervision of Generals Geary and Kane, was soon completed, and the remainder of the Twelfth Corps, with its pack trains and the entire Eleventh Corps, crossed the river on this bridge. A strong position was taken on the opposite side of the river.

At daylight on the following morning, the march was resumed, Geary's division leading. Just before the head of the column reached the Wilderness, an attack was made on our right flank by a small body of cavalry and two pieces of artillery. Two regiments were sent to drive away this force, while the main body continued its march.

The two corps arrived at Chancellorsville, Va., at about 2 p. m. on the 30th. The Twelfth Corps took position in the woods, on a line nearly parallel to the Plank road, with the left resting near Chancellorsville and the right near a church about 1 1/2 miles therefrom. The Eleventh Corps joined the right of the Twelfth, with its right resting on Hunting Run. The Fifth Corps, which had crossed at Ely's Ford and arrived at Chancellorsville before either of the others, extended from Chancellorsville toward the United States Ford. The major-general commanding the army arrived at Chancellorsville on Thursday evening, the 30th, and I then resumed the command of the Twelfth Corps.