The Service Building was the first exposition building to go up and the last to be given up. Its contract was let in October 1912, and on October 17 the first load of lumber for it was paraded through the city behind an automobile tractor. The crowd loved it, since it was the first physical proof that "the dirt was really beginning to fly" (Todd). It was done by mid-February 1913. On February 18 the Architectural and Engineering Departments moved in, and the Division of Works left its downtown offices at Pine and Battery Streets to direct construction "on the lot."
By opening day it was "as crowded as a tenement." It held the offices of the Division of Works, the Director of Exhibits, the Division of Concessions and Admissions, the Comptroller, Special Days and Events, and the guards' headquarters and school. Its court held the lost-and-found office and a barred lock-up that was never used. The ground floor of the south wing became the emergency hospital, run by the U.S. Public Health Service with two motor ambulances and a medical library. Janitors, telephones, the exposition's garage and a bandstand just to the north all clustered around it.
After closing day the exposition kept it off the salvage market because it still needed the building. The divisions directing the exodus and the wrecking stayed on here for months, and a sales office for salvaged steel and lumber was run from it.