Palm Beach International Airport began operations in 1936 as Morrison Field. It was named in honor of Grace Morrison, a key participant in the planning and organization of the airfield. The first flight departing the field was a New York-bound DC-2 operated by Eastern Air Lines in 1936. The airport was officially dedicated on December 19, 1936. In 1937, the airport expanded beyond an airstrip and an administration building when the Palm Beach Aero Corporation obtained a lease, built hangars and the first terminal on the south side of the airport. The new terminal was known as the Eastern Air Lines Terminal. The field was used by the U.S. Army Air Forces during World War II. Following the attack on Pearl Harbor, Morrison Field was used for training and later as a staging base for the Allied invasion of France, with numerous aircraft departing Morrison en route to the United Kingdom to take part in the D-Day invasion of Normandy. Morrison Field was a stopover for flights to and from India, via Brazil and West Africa. In 1947, the newly established U.S. Air Force returned ownership of Morrison Field to Palm Beach County. The name was then changed to Palm Beach International Airport one year later, in 1948. The airport was again used by the U.S. Air Force in 1951 and renamed Palm Beach Air Force Base under the control of the Military Air Transport Service (MATS). USAF operations occupied the north half of the airfield while civil operations and the airline terminal used the south half. MATS used the base for training with the host unit being the 1707th Air Transport Wing (Heavy), and its 1740th Heavy Transport Training Unit. The 1707 ATW was known as the "University of MATS", becoming the primary USAF training unit for all Air Force personnel supporting and flying heavy transport aircraft. These included C-124 Globemaster II, C-118 Liftmaster, C-97 Stratofreighter, and C-54 Skymaster maintenance training along with aircrew and transition pilot training. Nearly 23,000 airmen trained at Palm Beach AFB during the Korean War. The Air Weather Service used Palm Beach AFB as headquarters for hurricane research, flying the first WB-50D Superfortress "Hurricane Hunter" aircraft from the base in 1956. After several years of Palm Beach County fighting the Air Force presence in West Palm Beach, the Air Force started to close down operations there. The 1707 ATW was inactivated on June 30, 1959, and reassigned to Tinker AFB, Oklahoma. With the wing's departure, Palm Beach County took over airfield operations. The Air Force retained a small presence at the base with the 9th Weather Group becoming the main operational unit at Palm Beach AFB, performing hurricane and weather research for the Air Weather Service. The Air Photographic and Charting Service (APCS) moved its 1370th Photo-Mapping Wing to the base, performing geodetic survey flights. The Air Force finally closed Palm Beach AFB in 1962, and all property was conveyed to Palm Beach International Airport the same year. Delta Air Lines began scheduled flights in 1959 and Capital Airlines in 1960. The first turbine-powered flights were Eastern Airlines Lockheed L-188 Electras in 1959, and Eastern DC-8 nonstops to Idlewild started in December 1960. Air Force One was a frequent visitor to PBI during John F. Kennedy's presidency in the early 1960s. Local voters defeated a proposal to relocate the airport around this time, instead choosing to expand the existing facilities. In October 1966, an eight-gate Main Terminal opened on the northeast side of the airport; in 1974 Delta Air Lines moved into its own six-gate terminal with the airport's first jetways. The Federal Aviation Administration (FAA) built a new air traffic control tower on the south side of the airport during this period. By the mid-1970s, the airport's dominant carriers were Delta, Eastern and National. Eastern operated the airport's only widebody service at the time, daily L-1011s to New York JFK and Newark.