The 499th Signal Detachment was constituted in the Army of the United States on 10 October as the 3499th Signal Service Company and activated on 6 November 1944 in Panama. It was redesignated as the 3499th Signal Equipment Installation Detachment on 21 April 1945. On 27 February 1947 it was deactivated in Panama. On 6 October 1965 the 3499th was redesignated as the 499th Signal Detachment and allotted to the Regular Army. It was activated at Fort Benning, Georgia on 7 October 1965 as part of the 281st Aviation Company (AML) (-) Task Force. The 499th Signal Detachment deployed with the 281st to Nha Trang, RVN in 1966. The Detachment was a separate entity with its own Command structure and was attached to the 281st to provide the next higher echelon of Avionics support. The unit remained attached to the 281st until its deactivation at Nha Trang on 25 November 1968 when its assets and personnel were absorbed by the 281st. On 14 July 1969 the 499th Signal Detachment was reactivated in Thailand and was operational there until its deactivation on 31 December 1970. The 499th was awarded the Republic of Vietnam Cross of Gallantry with Palm, Streamer embroidered "Vietnam 1967-1968."