The United States Army North (ARNORTH) is a formation of the United States Army. An Army Service Component Command (ASCC) subordinate to United States Northern Command (NORTHCOM), ARNORTH is the joint force land component of NORTHCOM. ARNORTH is responsible for homeland defense and defense support of civil authorities. ARNORTH is headquartered at Fort Sam Houston, Texas. Redesignated ARNORTH in 2004, it was first activated in early January 1943 as the United States Fifth Army, under the command of Lieutenant General Mark W. Clark.