HEADQUARTERS THIRTEENTH ARMY CORPS,
Camp near Vicksburg, June 2, 1863.

COLONEL: I have the honor to report that Maj. Gen. B. M. Prentiss, on the 23d ultimo, sent the steamer Pike on an expedition down the river for the purpose of obtaining recruits for the Second Regiment Arkansas Volunteers, of African descent, under command of Lieut. Col. George W. De Costa, of that regiment, with detachments of the First Indiana Cavalry and Thirty-sixth Iowa Infantry, and 25 men of the Second Arkansas Regiment, with one howitzer.
The expedition proceeded to a point on the Arkansas side 1 mile from Napoleon, Ark., and returned on the Mississippi side, making frequent marches into the country; in some instances to a distance of 6 or 7 miles.
General Prentiss bears testimony to the soldierly conduct of the soldiers, both white and black, as reported by the commanding officer.
Near Island No. 65 the Pike was fired into by a party of about 150 rebels, and brisk firing was kept up for some time, the enemy having two pieces of artillery, one of which was silenced by the howitzer on the Pike.
Captain [Benjamin J.] Waters, of the Second Arkansas Regiment, was severely wounded in the leg, and 2 colored soldiers were mortally wounded.
The enemy are supposed to have lost 10 or 15 killed and wounded.
The conduct of the colored soldiers was highly creditable, fighting with hearty good will and doing good service.
The expedition was eminently successful, capturing 75 mules, 8 horses, and subsistence for the whole force.
The colored population hailed with joy the appearance of the colored soldiers. One hundred and twenty-five recruits were obtained on the expedition. The regiment is rapidly filling up, and it is hoped it will be full in a few days.

Your most obedient servant,

WALTER B. SCATES,
Lieutenant-Colonel and Assistant Adjutant-General.

Lieut. Col. JOHN A. RAWLINS,
Assistant Adjutant-General.