X Corps (United States)

Infobox Military Unit
unit_name=X Corps


caption=X Corps shoulder sleeve insignia
dates=May 1942–March 1968
country=United States
allegiance=Federal
branch=Regular Army
Army Reserve
type=Corps
role=
size=
command_structure=
current_commander=
garrison=
ceremonial_chief=
colonel_of_the_regiment=
nickname=
patron=
motto=
colors=Blue and WhiteDuring the Korean War, the insignia was worn with the white side upward.Fact|date=June 2008
march=
mascot=
battles=World War II
Korean War
notable_commanders=
anniversaries=

X Corps was a corps of the United States Army in World War II and the Korean War.

World War II

The X Corps was activated in May 1942 at Sherman, Texas. It embarked for the Pacific Theater in July 1944 after two changes of station and participation in maneuvers in Louisiana and at the California-Arizona maneuver area.

X Corps took part in the following campaigns: New Guinea, Leyte, and Southern Philippines.

As part of the Sixth Army, X Corps took part in the Philippines campaign of 1944–45, beginning with the invasion of Leyte. For its involvement, the X Corps received the Philippine Presidential Unit Citation with a streamer embroidered 17 October 1944–4 July 1945.

X Corps became inactive in 1946.

Korean War

During the Korean War, it took part in Operation Chromite, the landings at Inchon where it had the 1st Marine Division, the 7th Infantry Division and other US Army units under its command. The embryonic planning group for CHROMITE originally was known to insiders as "Force X" and the entire scheme was cloaked in absolute secrecy; to outsiders the small planning staff was known only as the Special Planning Staff of general headquarters, Far East Command. As the organization grew, due to bureaucratic entanglements supply orders were rejected because "Force X" was not referenced as a proper organization anywhere in Army manuals. General of the Army Douglas MacArthur (Supreme Commander Allied Powers) asked his Chief of Staff, Major General Ned Almond, to suggest a new name. Force X's Roman numeral ten reminded Almond of a corps which had fought under MacArthur in the last war—"why not call it the X Corps?" he asked. MacArthur was delighted and approved of the name. General Almond was subsequently chosen by MacArthur as X Corps' new commander.

The Marines first captured an island offshore of Inchon as a prelude to the assault and at the next tide, the main attack went in. Despite the noise of the attack on the offshore island, it completely surprised the North Korean forces. The Marines then moved on to the capital city of Seoul; in heavy fighting they eventually drove out the North Korean defenders. The US Army's 7th Infantry Division, which had landed later at Inchon, engaged the enemy on the outskirts of Seoul, destroying an armored regiment.

Inchon had a very large tidal range, and was thus very risky to use as a landing site. Nonetheless, the landing proved to be an enormous success. It is by far the largest amphibious assault to have taken place since World War II, and one of the boldest.

After the landing at Inchon, X Corps initially attacked up the Korean peninsula on the left wing of Eighth Army. However, it was withdrawn from the line relatively shortly thereafter to prepare for another amphibious assault, this time at Wonsan on the eastern coast. This action proved to be a mistake on two counts. First, forces of the Eighth Army moving by land reached the town before the assault went in. Second, it proved to be too far for UN forces to go. After landing at Wonsan, X Corps advanced inland towards Chosin Reservoir. The Chinese choose this moment to intervene in the war in force. X Corps was strung out along many miles, and under the Chinese attacks some units disintegrated. However, the 1st Marine Division largely maintained cohesion, and began its famous fight to the sea from Chosin. Completely surrounded, it successfully engaged seven or eight Chinese divisions and managed to reach the relative safety of the coast, where it was evacuated along with US Army and UN forces that had fought there. U.S. Army Lieutenant Colonel John U. D. Page of the X Corps Artillery, distinguished himself during the period of 29 November to 10 December, 1950 during the Chosin Reservoir withdrawal, and was subsequently awarded the Medal of Honor for his actions.

After the retreat from Chosin, once its units had been put back on an even keel, X Corps went into the line, and remained there for the rest of the war. It is widely contended that X Corps remained outside of the direct command of Eighth Army too long. X Corps reporting directly to the Supreme Commander had been necessary for the Inchon landings and still defensible for the Wonsan attack. However, after it entered the main line, conventional military doctrine indicated that it should have been placed immediately under the command of Eighth Army. General Douglas MacArthur, the commander of the United States forces, was accused of favoritism towards Edward Almond, the controversial commander of X Corps, who was his former chief of staff and a personal friend.

After X Corps was placed under the command of Eighth Army, it performed with powerful strength for the rest of the war.

Post-Korean War

In the years following the Korean War, the X Corps continued to train reserve units.

Due to Army budget cuts at the height of the Vietnam War involvement, the X Corps was deactivated on March 31, 1968.