Second Brigade, Second Division, commanded by Colonel Charles H. Smith, First Maine Cavalry.

FIRST MAINE CAVALRY.

At the commencement of the month 300 men, commanded by Major Taylor, were absent with General Kilpatrick on his raid toward Richmond, and 84 men, commanded by Major Thaxter, were picketing the Rapidan in the vicinity of Ely's Ford. during the absence of General Custer's command 150 of Major Taylor's command were subsequently detailed to accompany Colonel Dahlgren, and reached the main body again with a loss of 45 men in killed, wounded, and missing. The detachment experienced some spirited fighting and much severe marching, and arrived in camp in detachments, mounted and dismounted, via Alexandria. By these active operations the number of serviceable horses present was reduced from 556 to 273. The casualties in the detachments with General Kilpatrick and Colonel Dahlgren were 52 killed, wounded, and missing. Once during the month a party of 50 and once a party of 100 men have relieved like details on Morrisville road fro three days' picket; otherwise daily picket detail has been 1 commissioned officer and 31 men.

March 21. -Fifty men, commanded by Captain Vaughn, went on a scout to Auburn and vicinity.

March 25. -Another party of 50 men, commanded by Captain Myrick, went on scout to Auburn. Sixty-two recruits have been received during the month. If called upon to take the field at once the deficiency in horses would compel the regiment to march with half its strength of fighting men. Number of miles traveled: Major Taylor's command, 300 miles; Major Thaxter's, 50 miles; Captain Vaughn's, 10 miles, and Captain Myrick's, 10 miles; total, 370 miles.

TENTH NEW YORK CAVALRY.

March 6. --Headquarters near Warrenton, Va. Veteran organization returned from State of New York, having recruited about 250 men; 150 have already reported to the regiment; balance are at Camp Stoneman awaiting equipments. Regiment has made one scout during the month and captured 4 prisoners. The duty has been mostly picket and scouting; average number of miles marched, 60. No casualties during the month; small-pox reported in the regiment last month has entirely disappeared. Condition of horses improving.

SIXTEENTH PENNSYLVANIA CAVALRY.

Captain Snyder, Lieutenants Swank and Roberts, with 96 men, returned rom the command of General Kilpatrick, having been on raid to Richmond, with loss of Private John Mehaffey, of Company F. During the mouth regiment did picketing at Morrisville, of 100 men and 3 officers at each detail.

THIRTEENTH PENNSYLVANIA CAVALRY.

March 9. --A scout of 40 men, under the command of Lieutenant White, was attacked by the enemy in the vicinity of Greenwich. The party making the attack was composed of the Fourth Virginia