At the beginning of May 1863, the 2d U.S. Cavalry’s regimental strength with the Army of the Potomac was 17 officers and 304 enlisted men in ten companies. Although authorized twelve companies, Company M was not yet mustered and Company C had just reached Washington from the western theater. The regiment was commanded in May by Major Charles J. Whiting, the only field grade officer present for duty with his regiment of the four regular cavalry regiments in the Army of the Potomac.

All ten companies with the army participated in Stoneman’s Raid, apparently with a steep bill in horseflesh. The monthly return shows 165 unserviceable horses in the regiment. Expiration of enlistments was fast becoming a problem as well, with 32 veterans departing the regiment this month. Average company strength was only 30. Not a single company had its full complement of officers. Of the ten companies, three were commanded by captains, four by first lieutenants and three by second lieutenants. All three of the second lieutenants were former first sergeants.
Source: NARA, Returns of Regular Army Regiments, 2d U.S. Cavalry, April 1863, images 223-224.