Organized 23 May 1923 from new and existing units in the Oklahoma National Guard as the 120th Medical Regiment and assigned to the 45th Division (later re-designated as the 45th Infantry Division). Inducted into Federal service 16 September 1940 at home stations. Reorganized and re-designated 11 February 1942 as the 120th Medical Battalion. Inactivated 17–24 November 1945 at Camp Bowie, Texas. Reo
rganized and Federally recognized 10 December 1946 with Headquarters at Norman. Ordered into active Federal service 1 September 1950 at home stations. (120 Medical Battalion [NGUS] organized and Federally recognized 7 January 1953 with Headquarters at Oklahoma City) Released 30 April 1954 from active Federal service and reverted to state control, with Headquarters at Oklahoma City; Federal recognition concurrently withdrawn from the 120th Medical Battalion [NGUS]. Relieved 1 February 1968 from assignment to the 45th Infantry Division; Battalion concurrently broken up and its elements reorganized and redesignated as follows:
Headquarters and Company A as Headquarters and Headquarters Detachment, 120th Medical Battalion. Company B as Company B, 700th Support Battalion, an element of the 45th Infantry Brigade. Company C as Headquarters and Headquarters Company, 120th Supply Service Battalion - hereafter separate lineage. Company D as the 145th Medical Company - hereafter separate lineage. Headquarters and Headquarters Detachment, 120th Medical Battalion, consolidated 1 October 1996 with the 700th Support Battalion and consolidated unit designated as the 700th Support Battalion, an element of the 45th Infantry Brigade. Organized and Federally recognized 1 April 1963 from existing units in the Oklahoma Army National Guard at Oklahoma City as the 120th Supply and Transportation Battalion and assigned to the 45th Infantry Division. Reorganized and redesignated 1 February 1968 as the 700th Support Battalion (45th Infantry Division concurrently reorganized and redesignated as the 45th Infantry Brigade)
