The Century of Progress Exposition was an international exposition held in Chicago, Illinois in 1933 and 1934. The exposition was a world's fair that celebrated Chicago's centennial and a "century of progress" in science and industry.
One of the main buildings at the exposition was the Travel and Transport Building. This building was also the most unique. A dome was constructed on the principle of a suspension bridge for the first time in architectural history. The dome of the Travel and Transport building was suspended 125 feet above the ground by cables attached to twelve steel towers. The use of this suspension principle allowed for a large and unobstructed space for exhibits.
A century of progress in transportation was dramatically represented by exhibiting the latest current mode of transportation next to that of a century earlier. The old John Bull railroad engine, which first ran in 1831, was contrasted with one of the new Boeing monoplanes that was then in service on United Air Lines' routes.
The United Air Lines' plane was selected for exhibition in the Dome of the Travel and Transport Building because it represented the latest features of airplane design and construction. These features were described on the back of the postcards:
Powered with two 550 h. p. supercharged Wasp engines, these Boeing Monoplanes can cruise 171 m. p. h. They land at the low speed of 59 miles an hour and take off after a run of only 770 feet. They can climb 1320 feet a minute at sea level and to 10,000 feet in eleven minutes. Carrying a full load of ten passengers, two pilots, stewardess, luggage, mail and express, these planes can climb with only one of their two engines if necessary.
The plane shown on the postcard above could travel coast to coast in 20 hours. It was the same type that was on exhibit, and was one of fifty in service on United Air Lines' routes. That type was described as the "fastest multi-motored passenger mail-express plane" then in service in the world.
The postcard below shows a cutaway view of the plane. Ten passengers occupied comfortable reclining seats in the cabin, which was in charge of the stewardess. The pilot and mate controlled the plane from the cockpit. Mail, express, and baggage were carried in the compartments at the front and rear.
The last three postcards were furnished for writing and mailing from the Dome of the Travel and Transport Building at A Century of Progress. The stampbox contained these words: "Please address, stamp and drop card in slot provided. Mail collected several times daily."
One of the big events at the 1933 exposition was the arrival of General Italo Balbo and a fleet of 24 Italian seaplanes from Italy on July 15. This video shows "Unprecedented scenes at 'A Century of Progress Exposition,' where a million people, jamming the shore front of Lake Michigan, hail the Italian Air Minister and the intrepid crews of his twenty-four seaplanes upon the completion of their epochal mass flight from Orbetello, Italy."