Organized at Indianapolis, Ind., June 20, 1861, and mustered in July 9, 1861. Assigned to 1st Indiana Cavalry as Company "K," August 20, 1861, but served detached from Regiment entire time. Served in the Dept. of West Virginia as Escort to Gen. Rosecrans July to November, 1861. At Headquarters Dept. of Western Virginia and Dept. of the Mountains to June, 1862. At Headquarters 1st Army 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, participating in all the services of these headquarters. Old members mustered out June 23, 1864. Veterans and Recruits mustered out May 31, 1865. Camp Allegheny, Greenbrier, W. Va., December 13, 1861. Expedition to Huntersville December 31, 1861-January 6, 1862. Huntersville January 3, 1862. Charge into Fredericksburg, Va., November 9, 1862. Duty at Glymont, Md., on lower Potomac, January to May, 1864. Joined Army of the Potomac at White House, and duty at Headquarters of Gen. Meade until mustered out.