Lieutenant General Walton Walker of the US Army ordered that ROK Army units, scattered by the North Korean invasion, be organized into two corps.

Thus the II Corps was born July 24, 1950, to defend the Pusan Perimeter.

They were operating in support of the ROK I Corps which was under the command of General Walker.

[2] On October 24, hoping to end the conflict quickly, General Douglas MacArthur, Commander of UN forces, ordered an offensive to the northern border of North Korea and form a defensive line at the Yalu River.

By November 4, 1950, the II Corps and the 8th Regiment of the US 1st Cavalry Division were destroyed.