The 81st Infantry Division was reactivated for World War II service in June 1942 at Camp Rucker, Alabama. As in World War I, the division was filled primarily with inducted men. The division trained at locations in Tennessee, Arizona and California before embarking for Hawaii in June 1944. After completion of amphibious and jungle training, the 81st Infantry Division departed for Guadalcanal in August 1944. There the division was attached to the III Marine Amphibious Corps reserve. In September 1944 the 321st and 322nd Infantry Regiment of the 81st Infantry Division performed a combat landing on Angaur Island as part of the operations to secure the Palau Islands chain. After finishing the battle of Angaur, the 81st Infantry Division was ordered to assist the 1st Marine Division in their efforts to seize Peleliu. The 81st Infantry Division eventually relieved the 1st Marine Division, and assumed command of combat operations on Peleliu. The 81st Infantry Division remained engaged in the Battle of Peleliu until the end of organized Japanese resistance on 18 January 1945. In early February 1945, the 81st Infantry Division sailed to New Caledonia to rest and refit. In May 1945, the 81st Infantry Division was deployed to the Philippines to take part in mopping up operations on Leyte Island, and to prepare for the planned invasion of Japan. After the end of World War II, the 81st Infantry Division deployed to Aomori Prefecture in Japan as part of the Allied occupation force. The 81st Infantry Division was inactivated in Japan on 30 January 1946.