Technology has been an important part of world's fairs since the first one in London in 1851, where agricultural reapers and Colt's revolvers were on display. But at the world's fairs in Chicago in 1933 and New York in 1939, technology gained far greater prominence, with spectacular, larger-than-life exhibits that showcased the latest in manufacturing and communications. Even though the country was still in the depression and admission prices were high (50 cents in Chicago and 75 cents in New York), the events were enormously successful, together attracting more than 90 million visitors.

Inventors had always flocked to world's fairs to show off their latest inventions. Automobiles, telephones, and electric lights all made their major public debuts at fairs before the 1930s. "If you were an inventor or manufacturer and you were trying to introduce a product or idea to the masses, a world's fair was a pretty good way to do it," says Robert Rydell, a history professor at Montana State University. But during the depression-era fairs, organizers gave scientists and corporations an opportunity to present technologies integrated into visions of a more prosperous future.