The 164th Infantry Regiment of the Americal Division went into action on Guadalcanal on 13 October 1942 alongside the 1st Marine Division as the first United States Army unit to conduct an offensive operation against the enemy in either the Pacific or European Theater of Operations during World War II. Eight other U.S. Army divisions began offensive combat operations in late 1942: the 32nd and the 41st Infantry Divisions in the Pacific on New Guinea; and in North Africa, the 1st, 3rd, 9th, and 34th Infantry Divisions, and the 1st and 2nd Armored Divisions.