Following the conclusion of the 1915 Panama-Pacific International Exposition, a board of army officers recommended the vacant bayfront site for an Air Coast Defense Station to supplement the artillery defenses of San Francisco Bay. The plan was approved in 1921 and implemented under the supervision of Henry “Hap” Arnold. Facilities were simple at best—a grassy, kidney-shaped field on which the outline of the Panama-Pacific International Exposition racetrack was still visible. In an era of canvas-wing biplanes, however, the site was ideal for an airfield—a wide expanse of grass to soften landings and slow the planes after touch-down.
Along the southern edge of Crissy Field, the army constructed hangars, workshops, and a garage. Farther east, a cluster of structures included an administration building, enlisted barracks, flagstaff, and a guardhouse. On top of the bluff were bachelor officers' quarters and a row of small homes for married officers.