time line

Corps.... The Army's largest tactical unit, the instrument with which higher echelons of command conduct maneuver at the operational level. The corps staff is the principal planning and coordinating agency upon which the corps commander relies for the detailed preparation and oversight of his operations.

X Corps 1950 through 1955

Following the end of World War II, Tenth (X) United States Army Corps was one of the units which went into Japan as part of the army of occupation but, as the size of U.S. forces in Japan dwindled, it was deactivated on 31 January 1946.

12 September 1950 X-Corps, under command of Major General Edward M. Almond, was reactivated. Simultaneously, it assumed command of the U.S. 7th Infantry Division and the U.S. 1st Marine Division.

15 September 1950 Three days after activation X-Corps, as part of Joint Task Force -7, made a successful combat assault landing at Inchon, South Korea, then quickly drove inland.

Following the fall of Seoul to UN forces, and the advance into North Korea, X-Corps, still independent of 8th US Army, Korea, was sent by ship to land at Wonsan on North Korea’s East Coast. X-Corps was augmented by the U.S. 3rd Infantry Division while the Republic Of Korea (ROK) 2nd, 5th and 8th Infantry Divisions came under X-Corps command in mid-October 1950.

With the Chinese intervention in November 1950, and the fighting withdrawal of 1st Marine and 7th U.S. Infantry Divisions from the Chosin (Changjin) Reservoir down narrow, Chinese-lined roads to safety, X-Corps was withdrawn from North Korea with the last units leaving Hamhung on 24 December 1950. The same day, X-Corps ceased to be an independent command and came under 8th United States Army, Korea, command and control.

April 1951 X-Corps was reorganized when the U.S. 2nd Infantry and the ROK 7th Infantry Division were assigned, and the U.S. 3rd and 7th Infantry Divisions plus the ROK 5th and 8th Infantry Divisions were reassigned to other corps.

During March 1952, the U.S. 25th Infantry Division replaced the 2nd Infantry Division while the ROK 6th Infantry Division replaced both the ROK 2nd Infantry Division and the ROK 8th Infantry Divisions in X-Corps structure.

During January 1953, a final reorganization took place. The U.S. 25th Infantry Division, U.S. 1st Marine Division, and the ROK 6th Infantry Division were reassigned to other corps and were replaced by the U.S. 40th Infantry Division, U.S. 45th Infantry Division and the ROK 12th and 20th Infantry Divisions. The ROK 7th Infantry Division remained with X-Corps.

X-Corps departed Korea in 1955 and was deactivated at Fort Riley, Kansas, on 27 April 1955.