The Seattle World's Fair, also known as the Century 21 Exposition, took place between April 21 and October 21, 1962. The fair was originally conceived in 1955 as a celebration of the American West that would also commemorate the 50th anniversary of the 1909 Alaska-Yukon-Pacific Exposition, but it soon became clear that the projected date was far too ambitious. New operating dates were established, and fair organizers decided that a new theme was needed, as well. As the Space Race intensified, the United States grew increasingly determined to demonstrate its strength and leadership in the realms of science, technology, and space exploration to the rest of the world; thus, man's new role in the age of space became the fair's central theme. Five major areas, or "worlds," were developed to represent this new theme, each occupying its own separate area of the fairgrounds:

The World of Century 21--Housed in the Washington State Coliseum, this area featured exhibits by Pan American World Airways, General Motors, the American Library Association, and RCA, as well as Washington State's own circular exhibit entitled "The World of Tomorrow," which offered fairgoers a 21-minute audio-visual "tour of the future."

The World of Science--The United States Science Pavilion (now the Pacific Science Center) was built for the Seattle World's Fair and was designed by University of Washington alumnus Minoru Yamasaki, who would later design the World Trade Center. Inside the pavilion, the massive exhibit was divided into five major sections, the content and presentation of each conceived by a special advisory committee of over 100 internationally recognized scientists. Each section focused on a different aspect of science--development, methods, recent innovations and future implications--culminating in what was widely regarded as the greatest scientific exhibition ever conceived.

The World of Commerce and Industry--The largest and most varied of the fair's five themed areas, the World of Commerce and Industry consisted of two major divisions, foreign and domestic, and stretched to opposite ends of the fairgrounds. Dozens of foreign exhibits were housed in several buildings on the International Plaza and the International Mall. Thirteen domestic exhibitors, such as IBM, General Electric, Bell Telephone, and the Standard Oil Company of California, each had their own pavilions. Exhibits by H.J. Heinz and the National Cash Register Company, among others, were displayed in the block-long Hall of Industry, while the Interiors, Fashion, and Commerce Pavilion presented daily fashion and interior design shows, along with other commerical and industrial exhibits.

The World of Entertainment: This $15 million performance arts program featured the best in theater, music, dance, and sports from around the world. The 3,100-seat Opera House hosted performances by the Seattle Symphony Orchestra, the Folklorico Dancers of Mexico, and the New York City Ballet Company

The World of Art: Other important segments of the fair were the Food Circus, located in a large building near the center of the fairgrounds; the Gayway, which featured rides, midway games, and other amusements; and Show Street, the adult entertainment center of the fair. All areas were tied together by the Boulevards of the World, or Boulevard 21, which became known as the "shopping center of the fair."

The Pavilion of Electric Power, sponsored by the Electric Utilities of Washington, was located on Boulevard 21. It was built to showcase the hydro-electric potential of the state and to highlight innovative new methods for producing low-cost electricity. A 40-foot high dam formed the backdrop of the pavilion, over which three thousand gallons of water would spill each minute. Floating in a pond at the base of the dam was a 22-foot relief map of Washington State which featured illuminated plastic blocks, lamps, and neon tubing highlighting the principal power dams of the state, the transmission network and cities with populations over 10,000. A wide ramp led to an upper exhibit area containing three consoles which afforded fairgoers the opportunity to operate the electronic features of the map while a recorded narration described the future of low-cost power in Washington State. Other features of the pavilion included an old-fashioned waterway run by water from the dam which demonstrated early attempts to harness hydro-electric power, an animated display illustrating how nature's water cycle and dams work together to produce electricity, a model of an atomic power generating plant, and new methods of harnessing solar power-- the solar reflector and the silicon cell. The final exhibit described the beneficial by-products of the hydrolectric dam: irrigation, recreation, navigation, conservation, and flood control. An information booth was located on the upper level of the pavilion, with attendants available to answer questions and provide additional information on the production of electricity to visitors leaving the pavilion.