The State of Washington World's Fair Commission first met August 19, 1955; initially the Commission studied the feasibility of a fair. By December 1955, the Commission decided that with the proper support a fair was possible. The World's Fair Commission was enlarged in 1957 to fifteen members and included City Council member J. D. Braman. The fair was named the Century 21 Exposition in 1957. Seattle voters approved a $7,500,000 bond issue in 1956 for buildings and acquisition of land. The Seattle Civic Center Advisory Commission was created in December 1956 by Seattle City Council. In 1957, the State matched the 1956 bond issue approved by Seattle voters, approving an additional $7,500,000 for the fair.

World's Fair Corporation of Washington incorporated on October 9, 1957, created with members of the World's Fair Commission established in 1955 by the Washington State Legislature. Its purpose was to plan and operate the Exposition; its name was amended to Century 21 Exposition, Inc. on November 20, 1958. The Articles of Incorporation stated that the purpose of Century 21 Exposition, Inc was "to plan and present a World Fair at Seattle which will provide a spectacular vehicle for dramatizing, on behalf of and in cooperation with all such nations, their common hopes and aspirations, their historic, cultural and scientific achievements, the readiness for world leadership and their earnest desire to live in peace." A subcommittee of the World's Fair Commission was formed to pick a site; by 1956 the site of the Civic Auditorium was chosen. A Joint Executive Committee was formed representing Civic Center Advisory Commission and the World Fair Commission to expedite the development of preliminary plans for approval by the respective Commissions, and also address land acquisition.

The Seattle Civic Center Advisory Commission was responsible for choosing architects, building public support, exhibits, and overall design. The Washington State World Fair Commission was responsible for financial issues and land acquisition. There were advisory boards for cultural arts and design standards with committees for artists and sculptors, engineers, landscape and performing arts. Federal funds, as well as generous contributions from Seattle business people, contributed to the success of the fair. The Fair opened on April 21, 1962 and closed on October 21. The City took control of the fairgrounds in 1965 when the Seattle Center Department was created to administer, manage and control the facilities on the site of the 1962 World's Fair. The Center's purpose is to be an active civic center providing facilities and programs supporting the arts, education, s ports and entertainment. In addition, there are four facilities on the grounds that are not owned by the City: the Space Needle, Memorial Stadium, the Pacific Science Center, and the Experience Music Project.