The U.S. Post Office Department produced this silent documentary tracing the transcontinental route flown by its airmail carriers as of 1923. This edited version of the original 32-minute film follows a letter from the New York Post Office until it lands in its mail bag at San Francisco. En route, the airmail pilot flies a DeHavilland DH.4 westward from Long Island. Landmarks and refueling stops include major cities from New York to Cleveland, Chicago, Omaha and Cheyenne; mountain ranges from the Alleghenies to the Rockies, and rivers and railroad tracks. When the airmail plane reaches the Sacramento valley, it overtakes the Overland Limited train that left New York three days before it did, proving the speed and eventual dominance of airmail service.
Video: U.S. Post Office Department, Courtesy National Archives and Record Administration (13:46