Alfred C. Clas

He advanced to a partnership with Douglas in 1885–86 and then worked independently for a few years prior to creating the firm Ferry & Clas with George Bowman Ferry in 1890. The Pabst Mansion at 2000 West Wisconsin Avenue in Milwaukee was the first project of the Ferry & Clas partnership and was completed in 1892.

Ferry and Clas were responsible for much of the city planning and development that was happening at the time. Clas was a City Planner and a member of City Park Board and designed the Milwaukee Auditorium and other public buildings. Ferry & Clas was dissolved in 1912, when Clas partnered with his son Angelo to form the firm Clas & Clas. In 1921 that partnership was restructured as Clas, Shepard & Clas by the addition of his son Reuben and John S. Shepard as junior partners. Shepard withdrew in 1931 and the firm became Clas & Clas, Inc., with Alfred Clas remaining president until his death in 1942.

The City of Milwaukee commemorated a park in Clas's name in appreciation of his work as a city planner. Alfred C. Clas Park is located in Milwaukee County, just off N. 9th St and Wells St (Latitude: 43.0405556, Longitude: -87.9238889), on the southern side of the Milwaukee County Courthouse.

He was a member of the American Institute of Architects.