Intended to celebrate the centennial of the founding of Chicago, the Century of Progress-Exposi-- tion was a powerful event at its opening, thanks to its upbeat emphasis on scientific progress in stark contrast to the gloomy Depression atmosphere of the time. Architectural novelty was a trademark of the show, which included a cable-suspended dome inspired by the suspended bridge, as were unique forms of entertainment, including the visit of the Graf Zeppelin airship in the fall of 1933. The most popular exhibit of 1934 was the Industrial Hall, in which the latest technological innovations of Ford were displayed. By the time it closed, the exposition had attracted about sixteen million visitors.

Source:

Robert W. Ryddell, "The Fan Dance of Science: America's World's Fairs in the Great Depression," Isis, 76 (December 1985): 525-542.