The United Aircraft and Transport Corporation was formed in 1929, when William Boeing of Boeing Airplane & Transport Corporation 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 airframe and aircraft engine manufacturing and airline business, to serve all aviation markets, both civil aviation (cargo, passenger, private, air mail) and military aviation.