With the closing of the California Pacific International Exposition, the Ford Building closed its doors to the general public and remained closed to the public until 1980 when the San Diego Aerospace Museum moved in.

In the intervening years, the building served many purposes. The National Guard’s 251st Coast Artillery Regiment stored its anti-aircraft artillery, trucks and searchlights here, until the unit was drafted in 1940 and shipped to Hawaii. In 1941, the San Diego Vocational School set up an airplane construction school in the Ford Building where men and women learned the trade and became aircraft workers during World War II. The Civil Air Patrol held night school in the Ford Building for several years. Following a dispute between the city and the city Schools over responsibility for building repairs, the aviation school moved out in 1946.

Convair considered using the building in 1947, but backed out when they learned the pavilion could not accommodate the 110 feet wing span of its B-24 Liberator. That same year, San Diego’s city manager authorized the collection of airplanes for an exhibit in Balboa Park. Perhaps this explains the Japanese Kawanashi N1K1 “George” fighter plane found sitting unappreciated in the basement for several years. The aircraft was later given to the Air Force Museum in Dayton, Ohio. The National Rifle Association tried to get the Ford basement for firing ranges, but later decided against this plan after calculating the cost of adapting the building.

The Ford Building then fell into disrepair and was used primarily as a storage warehouse for the city’s Park and Recreation department. What had once been called a “paragon of Streamline Modern architecture” had become a “white elephant” and was scheduled for demolition. The Bartholomew Master Plan of 1960, commissioned by the city, reported the Ford Building to be “lacking in architectural significance.”

This report prompted many concerned citizens of San Diego to get involved in a plan to save the building by placing it on the National Register of Historic Places in 1973. It was at this time that the San Diego City Council declared The Ford Building as the new home for the San Diego Aerospace Museum.