The 684 Monadnock Block address used in the ads was the architectural office of H.K. Holsman, who was already a noted architect and engineer before beginning the car company. The 6th floor office in the Monadnock Building also served as the mailing address for his car company, and he continued his architectural design work there after selling the car company. The Holsman Automobile Company was located at what was then 63rd. Street & Washington Avenue, which was later renamed Blackstone Avenue, on the South East Side. The factory building is long gone.
