The Century of Progress World's Fair - held in Chicago in 1933 and again in 1934 - was among the most successful World's Fairs of all time, actually turning a profit. It was also the launch-pad for Tru Vue's toy-format 3D filmstrip system, which documented the Fair over 8 different filmstrips. This is the first one.
3D Photos of Chicago’s Century of Progress World’s Fair – Part 1
