In 1907, William S. Harley graduated from the University of Wisconsin–Madison with a degree in mechanical engineering. That year, they expanded the factory with a second floor and later with facings and additions of Milwaukee pale yellow ("cream") brick. With the new facilities, production increased to 150 motorcycles in 1907. The company was officially incorporated that September. They also began selling their motorcycles to police departments around this time, a market that has been important to them ever since. In 1907, William A. Davidson quit his job as tool foreman for the Milwaukee Road railroad and joined the Motor Company.