US Airways traces its history to All American Aviation Inc, a company founded by du Pont family brothers Richard C. du Pont, Alexis Felix du Pont, Jr. and CEO Steven Gardner. Headquartered in Pittsburgh, the airline served the Ohio River valley in 1939. In 1949 the company was renamed All American Airways as it switched from airmail to passenger service; it became Allegheny Airlines in 1953.
Allegheny's first jet was the Douglas DC-9 in 1966; it absorbed Lake Central Airlines in 1968 and Mohawk Airlines in 1972 to become one of the largest carriers in the northeastern United States and sixth largest airline in the world as measured by passenger boardings.
But with expansion came growing pains: by the 1970s Allegheny Airlines had the nickname "Agony Air" due to customer dissatisfaction with the carrier's service.
Allegheny's agreement with Henson Airlines, the forerunner to today's US Airways Express carrier Piedmont Airlines, to provide service under the Allegheny Commuter banner, is regarded as the industry's first code-share agreement, a type of service now offered throughout the industry.