The 23rd Infantry Division, initially, and more commonly known as, the Americal Division, of the United States Army was activated 27 May 1942 on the island of New Caledonia. In the immediate emergency following Pearl Harbor, the United States had hurriedly sent three individual regiments to defend New Caledonia against a feared Japanese attack. This division was the only division formed outside of United States territory during World War II (a distinction it would repeat when reformed during the Vietnam War).