How the Mail Built the Airlines: Aviation’s Unlikely Founding Industry

The first sustained business of American aviation was not carrying people but carrying letters. After the First World War left a surplus of aircraft and trained pilots, the U.S. Post Office launched scheduled Air Mail service in 1918, and within a few years airmail pilots were flying the transcontinental route, navigating at first by landmarks and later by a chain of lighted beacons strung across the country so the mail could fly at night. It was dangerous work — the early airmail pilots had a brutal fatality rate — but it proved that aviation could operate as a reliable, scheduled service rather than a barnstorming stunt. The decisive turn came with legislation. The Air Mail Act of 1925 (the Kelly Act) allowed the Post Office to contract airmail routes to private carriers, and the Air Commerce Act of 1926 established federal oversight of civil aviation. Suddenly there was money, structure, and a route map. The companies that won those mail contracts used the revenue to buy bigger aircraft, and bigger aircraft had room for passengers. Carriers with names that echo through aviation history — the corporate ancestors of United, American, and others — grew directly out of airmail routes. The mail paid the bills while the passenger business was still an afterthought. By the 1930s the balance had tipped, and purpose-built airliners like the Douglas DC-3 finally made carrying people profitable on its own. But the network they flew, the navigation infrastructure they used, and the companies themselves were inheritances from the airmail era — an industry that began, improbably, with a sack of letters in an open cockpit.