Harold Pitcairn (1897-1960) founded Pitcairn Aviation in 1927 as an airmail carrier. In 1930, the new owner, Clement Keys (1896-1952), renamed it Eastern Air Transport and added passenger service along the Eastern Seaboard. Edward "Eddie" Vernon Rickenbacker (1890-1973), a World War I fighter pilot, became vice president in 1933, general manager in 1934, and after purchasing the airline in 1938, its president. In 1934 Eastern Air Transport changed names to Eastern Air Lines (also known as Eastern) and continued to expand its airmail and passenger routes. In 1956 Colonial Airlines merged with Eastern.

Eastern Air Lines became the main air carrier on the east coast, and was known as one of the “Big Four” airlines that dominated the industry, along with United, Trans World Airlines (TWA), and American. Eastern was headquartered in Miami, Florida, one of its hubs alongside Atlanta, Georgia. The cost of jet equipment, rising fuel costs, a more unionized workforce, and the 1978 airline deregulation law caused Eastern to accumulate debt in the 1970s. Consequently, Eastern Air Lines become a low-fare airline, and Francisco "Frank" Anthony Lorenzo (1940- ) purchased it in 1986. Despite new ownership, the company was liquidated in 1991.