Antonio B. Won Pat International Airport was built by the Japanese Navy about 1943, calling the military airfield Guamu Dai Ni (Guam No. 2) as part of their defense of the Marianas. After the island was recaptured by American forces in 1944, it was renamed Agana Airfield, due to the proximity of the town. After being repaired by Seabees of the 5th Construction Brigade in October 1944, the United States Army Air Forces Seventh Air Force used the airfield as a base for the 11th Bombardment Group, which flew B-24 Liberator bombers from the station until being moved to Okinawa in July 1945. With the reassignment of the heavy bombers, the 41st Photographic Reconnaissance Squadron flew long-range reconnaissance aircraft (F-5 Lightnings) from the field until January 1946.

After the war, the USAAF used the airfield for fighter defense of the Marianas (21st Fighter Group), (549th Night Fighter Squadron) until early 1947 and as a transport hub (9th Troop Carrier Squadron). In 1947, the USAAF turned over the airfield to the United States Navy, which consolidated its facilities with those at the closing Harmon Air Force Base in 1949, and operated Naval Air Station Agana until it was closed by the 1993 Base Realignment and Closure Commission.

Civilian use

Travel to Guam was restricted to military personnel with a security clearance until 1962. During these early years, a single Quonset hut served as Guam’s air terminal. The lifting of this travel restriction spurred the development of the airport. It’s International Air Terminal opened in March 1967 and accommodated its first tour group from Japan two months later.  Operations of the terminal were passed onto the Government of Guam’s Department of Commerce in 1969. In 1975, the Guam International Airport Authority (GIAA) was created as a separate agency. After NAS Agana was closed in April 1995, GIAA took over the entire airport’s operations. A new passenger terminal building was opened in 1982, and the current, much larger terminal building was opened in phases between 1996 and 1998.

https://www.guamairport.com/corporate/about-our-airport/history