1st Field Force was originally created as Task Force Alpha in August 1965. Initially its mission was to control all U.S. Army forces in Vietnam, however in November 1965 it was renamed 1st Field Force and was restricted to directing military operations only in II Corps. The battle-ax shaped insignia was approved on 5th October 19651 and featured three diagonal stripes with an upward pointing sword. Like the USARV insignia, the blue stripe represented the United States whilst the red and yellow were taken from the flag of South Vietnam.
1. The Institute of Heraldry