[citation needed] Clas was born in Sauk City, Wisconsin.
[2] He and Ferry were responsible for much of the city planning and development that was happening at the time.
[5] Clas Park on the southern side of the Milwaukee County Courthouse is named for him.
[citation needed] He was a member of the American Institute of Architects.
[6] The Pabst Mansion at 2000 West Wisconsin Avenue in Milwaukee was the first project of the Ferry & Clas partnership and was completed in 1892.