Thomas F. (Tom) Hamilton claimed in 1927 to have 'been responsible for production of 42 types of airplane in past 19 years', but design of many was work of James S. McDonnell, founder of McDonnell Aircraft. Formed Hamilton Aero Manufacturing Co., Milwaukee, 1922, producing propellers, floats and various prototypes, all in Duralumin. H-19, 20, 21 and 22 were first built for sale, all single-engine high-wing with corrugated skin, by 1926 being sold with trademark Metalplane. H-43 and H-45 of 1928 were outstanding machines, latter Wasp-engined and 8 seats. Name changed 11 July 1927 to Hamilton Metalplane Co. Lost identity late 1928 in takeover by Boeing and United Aircraft, name surviving only in propeller company.