Converted and Redesignated 23 February 1942 as 100th Reconnaissance Troop (less 3rd Platoon), 100th Division (Headquarters and Headquarters Company, 200th Infantry Brigade, concurrently converted and redesignated as the 3rd Platoon, 100th Reconnaissance Troop, 100th Division). Troop ordered into active military service 15 November 1942 and reorganized at Fort Jackson, South Carolina as the 100th Cavalry Reconnaissance Troop, an element of the 100th Infantry Division. Reorganized and Redesignated 2 August 1943 as the 100th Reconnaissance Troop, Mechanized. Reorganized and Redesignated 7 September 1945 as the 100th Mechanized Reconnaissance Troop. Inactivated 11 January 1946 at Camp Patrick Henry, Virginia. Redesignated 15 October 1946 as Reconnaissance Platoon, 100th Airborne Division. Activated 2 December 1946 at Louisville, Kentucky. (Organized Reserves Redesignated 25 March 1948 as the Organized Reserve Corps; Redesignated 9 July 1952 as the Army Reserve). Reorganized and Redesignated 31 August 1950 Anti-tank Platoon, 100th Airborne Division. Reorganized and Redesignated 12 May 1952 as the 100th Reconnaissance Company, an element of the 100th Infantry Division. Inactivated 22 April 1953 at Louisville, Kentucky. Activated 9 April 1955 at Neon, Kentucky. Disbanded 17 April 1959 at Neon, Kentucky.