Wotan said:
Americal, in the pacific theatre
In August 1942, three unattached infantry regiments, along with some miscellaneous units, were formed into a provisional division on the French colony of New Caledonia in the Pacific. The division's name derives from "Americans in New Caledonia." In October 1942, the Americal Division became the first U.S. Army unit to go on the offensive, taking part in the attack on Guadualcanal. The Americal fought in New Guinea and the Philippines and was disbanded in Manila in October 1945.
In 1954, during the Korean War, the Americal Division was reestablished in Korea, again using three unattached infantry regiments. It only served in Korea for six months before it was again disestablished.
During the Vietnam War, the Americal Division was activated using three independent brigades, the 11th, 196th and 198th Light Infantry Brigades. This took place in September 1967. This time, the Pentagon, not willing to let a division not have a number, designated it the 23rd Infantry Division. However, even in official documents, the division was still called the Americal. The Americal, less the 196th Light Infantry Brigade, was deactivated in December 1971. The 196th LIB remained in Vietnam until June 1972, when it was the last combat brigade to leave Vietnam.
The Americal is unique in that it is the only U.S. Army division never to have been stationed in the United States or any of its possessions. Here's the division patch: