The Americal Division, the 23rd Infantry Division, served in World War II from 1942 to 1945 in the Southwest Pacific, in the Cold War from 1954 to 1956, and in the Vietnam War from 1967 to 1971 in Southern I Corps. It was the first Army unit to go on the offensive against the enemy in World War II, the only Army division in World War II to have a name and not a number, was always activated outside the United States, and always served in a jungle environment.