In the months preceding World War II, the U.S. Army entered into the first of many lease agreements with the City of Stockton (on August 15, 1940) to build and operate an Army training facility at Stockton Municipal Airport. Stockton Army Airfield was initially garrisoned by the 68th Air Base Group (Special) under the Air Corps Advanced Flying School. Between 1940 and 1945, Stockton Field served as a training installation under the West Coast Training Center (later Western Flying Training Command) headquartered at Santa Ana Army Air Base. Known sub-bases and auxiliaries of Stockton AAF were: Kingsbury Auxiliary Airfield (No 1) 38°05?31?N 121°21?32?W New Jerusalem Auxiliary Airfield (No 2) 37°40?43?N 121°17?58?W Modesto Auxiliary Airfield (No 3)n37°37?34?N 120°57?21?W Tracy Auxiliary Airfield (No 4) 37°41?19?N 121°26?26?W Franklin Auxiliary Airfield (No 5) 38°18?19?N 121°25?45?W In May 1944 all of the facility was consolidated into the 3033rd Army Air Forces Base Unit. Given the airfield's proximity to logistical facilities under the Army Air Forces and Army Service Forces, the site soon became a logistical hub for the U.S. Army in general and the Army Air Forces in particular. This resulted in an increased number of transport aircraft passing through Stockton Field. Military warehouse facilities included 46 miles (74 km) of tracks connected to the adjacent Southern Pacific and Western Pacific Railroads for delivery and distribution of a daily average of 200 railcars of military supplies. On March 2, 1945, the final class completed training and Stockton AAF was transferred from the control of the Western Flying Training Command to the Air Transport Command. With this transfer, the 3033rd AAFBU was redesignated as the 591st AAFBU. In October 1946 Stockton AAF was declared surplus. As 1,044.18 acres were in the process of being transferred to the War Assets Administration for disposal, 71.36 acres, consisting of a major portion of the former cantonment area including housing, storage facilities, and a sewage disposal plant, were leased to U.S. Army's Stockton General Depot located to the south in nearby Lathrop. The City of Stockton and the County of San Joaquin resumed operating the former Stockton Municipal Airport on December 16, 1946, under a joint (interim) license. On the 1,044.18 acres of leased land (950 acres of which comprise the airport now under license) there were approximately 175 buildings, including 50 airport-related structures which were included in the above described license. The buildings were primarily the Quartermaster 700-series and 800-series type construction with concrete foundations, wood floor, composition roof, and wood lap siding. On January 29, 1947, the 71.36-acres of former Stockton Field retained by the U.S. Army was officially named the Stockton General Depot Field Annex, then renamed Sharpe General Depot Field Annex in 1948, when Stockton General Depot was redesignated as Sharpe General Depot. The U.S. Army, with the exception of the Sharpe General Depot Field Annex, left Stockton Field by January 31, 1948; the same date that the City of Stockton and the County of San Joaquin jointly assumed administration over the airport (Stockton Record 1964). Sharpe General Depot Field Annex was formed from two parcels of land adjacent to the southwest portion of the current Stockton Metropolitan Airport. Sharpe General Depot Field Annex was operated by the U.S. Army as a separate, self-contained military post under Sharpe General Depot. With the rapid expansion of depot operations and facilities that occurred with the outbreak of the Korean War in June 1950, Sharpe General Depot Field Annex's name was changed to Sharpe General Depot Troop Field Annex to reflect its support mission. During this period, the site was used primarily for family housing, recreational, and other support facilities for Sharpe General Depot.