2/514th CAR (AA) became 639th Coast Artillery Battalion (Auto Weapons) on 20 January 1943, And was again redesignated as the 639th Anti Aircraft Artillery Battalion (Auto Weapons) on 15 May. The 639th deployed from the New York Port of Embarkation on 29 September 1944, and landed in France on 10 October 1944. The 639th was then relocated to Braunfels, Germany on 20 August 1945. The 639th returned to the continental US via the New York Port of Embarkation on 2 February 1946, and was deactivated at Camp Kilmer, and returned to the US Army Reserve on the same day.