The origins of the 39th Bombardment Wing began on 1 December 1958 when Strategic Air Command established the 4135th Strategic Wing at Eglin Air Force Base, Florida and assigned it to Second Air Force as part of SAC's plan to disperse its Boeing B-52 Stratofortress heavy bombers over a larger number of bases, thus making it more difficult for the Soviet Union to knock out the entire fleet with a surprise first strike. On 1 January 1959 the wing was reassigned to the 822d Air Division. The wing remained a headquarters only until 1 April 1959 when three maintenance squadrons and a squadron to provide security of the wing's special weapons were activated and assigned to the wing. It became fully organized in July, when the 301st Bombardment Squadron (BS), consisting of 15 Boeing B-52 Stratofortresses moved to Eglin from Ramey AFB, Puerto Rico where it had been one of the three squadrons of the 72d Bombardment Wing and the 54th Aviation Depot Squadron was activated to oversee the wing's special weapons. Starting in 1960, one third of the squadron's aircraft were maintained on fifteen-minute alert, fully fueled and ready for combat to reduce vulnerability to a Soviet missile strike. This was increased to half the squadron's aircraft in 1962. The 4135th (and later the 39th) continued to maintain an alert commitment until inactivated. In addition, the wing conduct final testing of the GAM-77 Hound Dog and the GAM-72 Quail air-launched cruise missiles from its B-52s as part of the testing program carried out by the Armament Division of Air Force Systems Command. The first launch of a Hound Dog by SAC was made by a wing crew on 29 February 1960 and the first Quail launch a few months later, on 8 June. In 1962 the 4135th Airborne Missile Maintenance Squadron was activated in November 1962 to maintain these missiles.