In December 1935, an airline consortium opened the first Airway Traffic Control Station for keeping aircraft safely separated as they moved between airports.

Air Traffic Control (ATC) was created as a direct response to the rapid growth of the aviation industry in the 1920s and the increasing danger of mid-air collisions. As more aircraft began using the same popular flight corridors and airports, the need for a centralized, "third-party" observer became apparent. The first "air traffic controller" is widely cited as Archie League, who began directing traffic at St. Louis Municipal Airport in 1929 using simple flags—a red flag for "stop" and a checkered flag for "go." By 1930, the first radio-equipped control towers were established to allow for communication beyond visual range. The system was further formalized in 1935 when several major airlines jointly established the first Airway Traffic Control centers to protect their investment and ensure the safety of their passengers. The primary goal was to provide "separation"—ensuring that aircraft were spaced far enough apart vertically and horizontally to prevent accidents. Over time, the purpose evolved to include the "orderly and expeditious flow" of traffic, helping planes land and take off in a sequence that maximized airport capacity while maintaining the highest possible safety standards.