The Auditorium was the one great exposition building meant to last, and it stood nowhere near the fairgrounds. The exposition built it on a city-provided site in the new Civic Center, bounded by Hayes, Grove and Larkin streets, "to house the many congresses and conventions" of 1915 (Official Guide), which the Guide put at nearly five hundred. By the season's end Todd counted 928. Delegates got halls rent-free and without paying admission to the grounds. Its main hall seated about 11,000, and smaller halls with sliding partitions could be divided into 26 meeting rooms.
It hosted the International Conference of Women Workers to Promote Permanent Peace on July 4–7, 1915, and a steady stream of congresses. On December 14, 1915, the Board of Supervisors formally named it the "Exposition Auditorium." On December 30, before about 3,000 people, President Charles C. Moore handed Mayor James Rolph a golden key, saying he rejoiced in the transfer: "It is a precious thought that out of the Exposition there should come so precious a heritage."
The great Austin organ from Festival Hall was moved here as always intended and dedicated by Edwin H. Lemare, the city's official organist, on April 8, 1917. In 1920 the building hosted the Democratic National Convention, the first national convention of a major party held west of the Rockies.
