In 1939, the U.S. Army Air Corps sent Major George C. Kenney to Puerto Rico to conduct a preliminary survey of possible air base sites on Puerto Rico. He examined a total of 42 sites and declared that Punta Borinquen the best site for a major air base. Planted sugar cane farms covered some 3796 acres that the government purchased for military use in the first week of September 1939 at a cost of $1,215,000. Later that year, Major Karl S. Axtater assumed command of what was to become Borinquen Army Airfield.
With the establishment of an independent United States Air Force in 1947, the complex was renamed Ramey Air Force Base in 1948. Ramey AFB was home to a succession of Strategic Air Commandstrategic reconnaissance wings and a bombardment wing, and housed a number of B-36 Peacemaker intercontinental bombers, albeit in its RB-36 strategic reconnaissance version. The RB-36s were later replaced by B-52 Stratofortress heavy bombers and KC-135 Stratotanker aerial refueling aircraft, while a tenant weather reconnaissance squadron operated WB-47 Stratojet and WC-130 Hercules aircraft. Due to the size and weight of the B-36, the runway at Ramey had to be built to a length of 11,702 ft and a width of 200 ft, with an added 870 ft Blast Pad at each end and an additional 50 ft shoulder on each side. The closure of Ramey Air Force Base began in 1971 as part of a SAC-wide reduction in bombardment wings and lasted until 1973. Following its closure, it was converted into a joint civilian-military airport with the U.S. Coast Guard comprising the remaining military aviation activities at the airport as Coast Guard Air Station Borinquen and Puerto Rico Air National Guard, Army National Guard and the United States Army Reserve maintaining non-aviation units.
Success with a test array and then a full scale forty element operational array at Eleuthera, Bahamas 1951-1952 led the Navy in 1952 to order six, quickly expanded to nine, undersea surveillance systems under the classified name of Sound Surveillance System to be installed under the unclassified name Project Caesar. The shore terminals were described as supporting "oceanographic research" and given the generic and ambiguous name "Naval Facility" with the actual submarine detection purpose classified on a strict need-to-know. The first of the systems was to terminate at a Naval Facility on a beach under the cliff of the Air Force Base. Construction began in 1953 with Naval Facility Ramey commissioned on 18 September 1954. In 1985 with mobile, towed arrays entering the system, SOSUS became the Integrated Undersea Surveillance System. SOSUS/IUSS mark their beginnings with the commissioning of Naval Facility Ramey. The facility, unlike NAVFAC Grand Turk and NAVFAC San Salvador completed later that year and not close to a military base, got support for all functions except its classified operations from the base. When the Air Force Base closed 1 January 1974 the facility became Naval Facility Punta Borinquen and self supporting until it was decommissioned 30 April 1976.