Organized at Terre Haute, Ind., for one year's State service April 25, 1861. Mustered in for three years' service July 4, 1861. Assigned to 1st Indiana Cavalry as Company "L," August 20, 1861, but served detached from Regiment entire term. Served in Dept. of West Virginia as Escort to Gen. Rosecrans July to November, 1861. At Headquarters Dept. of Western Virginia to March, 1862; and Dept. of the Mountains to June, 1862. At Headquarters 1st Corps, Army of Virginia, to September, 1862. At Headquarters 11th Army Corps, Army of the Potomac, to September, 1863, and at Headquarters Army of the Potomac to May, 1865. Participated in all the services of these headquarters. Old members mustered out July 3, 1864. Veterans and Recruits mustered out May 31, 1865.