A Century of Progress International Exposition was a World's Fair registered under the Bureau International
des Expositions, which was held in Chicago from 1933 to 1934. More colloquially known as The Chicago World's
Fair, it also celebrated the city's centennial. The theme of the fair was technological innovation. The fair's
motto was "Science Finds, Industry Applies, Man Adapts", which is beautifully expressed on Emil Zettler's
commemorative medal, a true Art-Deco masterpiece. The fair's architectural symbol was the Sky Ride, a
transporter bridge perpendicular to the shore on which one could ride from one side of the fair to the other.
One description of the fair noted that the world, "then still mired in the malaise of the Great Depression, could glimpse a happier not-too-distant future, all driven by innovation in science and technology." Fair visitors saw the latest wonders in rail travel, automobiles, architecture and, no kidding, cigarette-smoking robots. In art and architecture this period of the 1930's and 40's is sometimes called the Machine Age. It was dominated by the belief that technological progress was an unequivocal force for good and found expression in futuristic or stream-line designs.
The exposition was formally opened on May 27, 1933 by US Postmaster General James Farley at a four hour ceremony at Soldier Field. The fair's opening night began with a nod to the heavens. Lights were automatically activated when the rays of the star Arcturus were detected. The star was chosen as its light had started its journey at about the time of the previous Chicago world's fair—the World's Columbian Exposition—in 1893. The rays were focused on photoelectric cells in a series of astronomical observatories and then transformed into electrical energy which was transmitted to Chicago.
The fair buildings were multi-colored, to create a "Rainbow City" as opposed to the "White City" of the World's Columbian Exposition. The buildings generally followed Moderne architecture in contrast to the neoclassical themes used at the 1893 fair. One famous feature of the fair were the performances of fan dancer Sally Rand. Other popular exhibits were the various auto manufacturers, the Midway (filled with nightclubs such as the Old Morocco, where future stars Judy Garland, The Cook Family Singers, and The Andrews Sisters performed), and a recreation of important scenes from Chicago's history. The fair also contained exhibits that would seem shocking to modern audiences, including offensive portrayals of African-Americans, a "Midget City" complete with "sixty Lilliputians", and an exhibition of incubators containing real babies.
Much more information about the Chicago World's Fair is available at its Wikipedia entry.