United Aircraft and Transport Corporation

The United Aircraft and Transport Corporation was formed in 1929, when William Boeing of the Boeing firms teamed up with Frederick Rentschler of Pratt & Whitney to form a large, vertically-integrated, amalgamated firm, uniting business interests in all aspects of aviation—a combination of aircraft engine and airframe manufacturer and airline business, to serve all aviation markets, both civil aviation (cargo, passenger, private, air mail) and military aviation.

With headquarters at Hartford, Connecticut, the holding company controlled the stock of the Boeing Airplane Company of Seattle, the Chance Vought Corporation, the Hamilton Aero Manufacturing Company (a propeller manufacturer), and the Pratt & Whitney Aircraft Company, an aeroengine manufacturer. Sikorsky Aviation Corporation, the Stearman Aircraft Company of Wichita, Kansas, and the Standard Steel Propeller Company were added to United's portfolio shortly thereafter, followed by several more airlines brought into the fold. The airline interests were soon grouped under a new management company known as United Air Lines, Inc. However, the individual airlines (as well as the individual companies held by United) continued to operate under their own names.