Encouraged by Alameda's three existing aviation facilities, Congress funded Naval Air Station Alameda in 1937 after decades of advocacy by the Navy and local supporters, and the station was commissioned in 1940 following two years of dredging, filling, and construction on the former sites of Alameda Municipal Airport, Benton Field, and the San Francisco Bay Airdrome. Designed by the Navy's Bureau of Yards and Docks under planning overseen by Capt. Ben Morell, with construction directed by Cdr. E.C. Seibert, the project demolished most former airfield structures, built a stone rip-rap seawall, dredged silt from the future ship channel, turning basin, and Seaplane Lagoon, and spread millions of cubic yards of material over marshlands and tidal flats, adding more than 900 acres on the island's west end. By the end of 1939, construction was advancing under Cmdr. Harold J. Brow, and in 1940 the Administrative Core, Operations areas, and large seaplane hangars south of the base's core and repair facilities were well underway. That year Capt. Frank R. McCrary took command, the Navy expanded the planned base from 1,000 to 4,000 men, and emergency funding accelerated work, but the station was still unfinished when Japanese forces attacked Pearl Harbor and other U.S. possessions on December 7, 1941; construction was completed by the end of 1942. During the Second World War, the base became one of the West Coast's most important naval air stations, serving as a logistical supply base, aircraft repair facility, seaplane base, and homeport for dozens of aircraft carriers and other naval vessels, and it continued operating through the Korean and Vietnam Wars until its 1993 closure under the Base Realignment and Closure Commission. Its primary wartime mission was to supply Pacific Fleet ships and stations and repair damaged aircraft, with personnel in Building 5 overhauling more than 800 aircraft and more than 2,000 engines, while under Cptn. Walter F. Boone the station expanded to accommodate 22 aircraft squadrons, 23 ships, and 158 buildings. The Seaplane Lagoon, part of the Operations Area at the south end of the station, stood beside the seaplane hangars and taxiway; completed in 1940 at 3,000 by 1,500 feet and enclosed by bulkheads, walls, and jetties, it included an east-side dock extending 725 feet south and 1,000 feet west, with water dredged to 30 feet for ocean-going ships. The docks were designed to berth up to two aircraft carriers or similar vessels on each side and also moor smaller craft and officers' barges, while three ramps completed between 1940 and 1941 along the north edge of the lagoon allowed seaplanes to be fitted with wheels, hauled tail first by tractor across the taxiway, and taken to the seaplane hangars for washing, maintenance, and refurbishment. In 2013, part of the former station, including the Seaplane Lagoon, was designated the Naval Air Station Alameda National Register Historic District for its significant role as a West Coast military installation during the Second World War.
