NINTH UNITED STATES ARMY CORPS
(IX-CORPS)
During the occupation of Japan, U.S. IX-Corps was headquartered at Sendai, Japan and commanded the 1st Calvary Division and the 7th Infantry Division. It was deactivated during the downsizing reorganization of occupation forces on 28 March 1950. With the outbreak of the Korean War, IX-Corps was reactivated at Fort Sheridan, IL, on 10 August 1950, with personnel from 5th Army Headquarters. IX-Corps staff and support units arrived in Korea on 22 September 1950 and became operational on 23 September 1950 when it assumed command of the U.S. 2nd and 25th Divisions.
Following the withdrawal from North Korea during which both the 2nd and 25th Infantry Divisions suffered severe losses in both men and equipment to point these divisions were no longer capable of combat the 2nd and 25th Infantry Divisions were transferred to 8th Army reserve and IX-Corps took command of the 1st Calvary Division, the 24th Infantry Division, the 1st Marine Division, the 6th ROK Infantry Division and the 187th Airborne Regimental Combat Team (ARCT.)
More reorganization took place in March 1951 when the 1st Marine Division and 187th ARCT transferred from IX-Corps command and were replaced by the U.S. 7th Infantry Division and the ROK 2nd Infantry Division.
In January 1952, with the exception of the U.S. 7th Infantry Division, all other divisions were transferred to other Corps command while IX-Corps received the 45th Infantry Division (Oklahoma National Guard.) IX-Corps was further augmented in March 1952 with the U.S. 2nd Infantry Division and ROK 2nd and 3rd Infantry Divisions plus the Capital ROK Division. At the same time the U.S. 40th Infantry Division (California National Guard) replaced the U.S. 45th Infantry Division.
A final reorganization took place during January 1953 when all divisions except U.S. 3rd Infantry Division and Capital ROK Division were transferred to other corps. IX-Corps received the 9th ROK Infantry Division at this time.
IX-Corps left Korea for Okinawa in November 1956.
