 Having sold Henderson Motorcycle to Ignaz Schwinn's Excelsior Motor Manufacturing & Supply Company, founder William G. Henderson continued to work there until 1919, when differences of opinion regarding the design direction of Henderson motorcycles led to his resignation from Excelsior.In the fall of 1919, with the support of Max M. Sladkin of Haverford Cycle Co., Henderson started the Ace Motor Corporation in Philadelphia, Pennsylvania.The Ace motorcycle resembled the Henderson in general form, being a longitudinal four-cylinder motorcycle with chain drive, but Henderson had to be careful not to infringe any trademarks or patents that would have been owned by Excelsior at the time.