In Aug., 1862, James N. Schoonmaker, a citizen of Pittsburg, and a lieutenant in the 1st Md. cavalry, was authorized by Sec. Stanton to recruit a battalion of five companies of cavalry. Recruits were rapidly obtained and authority was given to recruit a full regiment. With the exception of one company from the Philadelphia area, its recruits were from western Pennsylvania. The men were principally from the counties of Allegheny, Fayette, Armstrong, Washington, Lawrence, Erie and Warren, and the city of Philadelphia. The regiment's original commander, Colonel James M. Schoonmaker, was one of the youngest regimental comman-ders in the Union Army at 20 years old. Pittsburgh attorney William Blakeley was the regiment's original lieutenant colonel. The three original Majors were Thomas Gibson, Shadrack Foley, and John M. Daily. Most of its fighting happened in the last half of 1863 and full year 1864. The regiment fought mainly in West Virginia and Virginia, often as part of a brigade or division commanded by Brigadier General William W. Averell and later Brigadier General William Powell. Among battles where the regiment saw significant action were the Battle of White Sulphur Springs, Battle of Droop Mountain, Battle of Moorefield, and the Third Battle of Winchester. It had two officers and 97 enlisted men killed or mortally wounded. Disease killed 296 enlisted men. Captain Thomas R. Kerr won the Medal of Honor for capturing a regimental flag at Moorefield where he was an advance scout, while Schoonmaker received the same award for action at the Third Battle of Winchester. Companies Company A - Philadelphia County and Allegheny County Company B - Allegheny County and Fayette County Company C - Allegheny County and Erie County Company D - Allegheny County Company E - Fayette County, Allegheny County, and Beaver County Company F - Allegheny County, Armstrong County, and Fayette County Company G - Allegheny County Company H - Washington County and enrolled in Allegheny County and Crawford County Company I - Erie County and Warren County Company K - Armstrong County Company L - Armstrong County Company M - Armstrong County and Westmoreland County