Career
Born in Hanover in the Kingdom of Hanover, Koch came to the United States as a toddler. His architectural career began at the age of 16 when he worked for early Milwaukee architect, G. West. Mygatt. He enlisted in the Civil War with the 24th Wisconsin Infantry as a private, later becoming a draftsman on General Philip Sheridan"s staff
After the war he returned to Milwaukee, where he formed a partnership with Mygatt until 1870, when he started his own firm.
One of Koch"s most significant works was the 1895 Milwaukee City Hall. Koch designed buildings for the University of Wisconsin.
He designed 26 courthouses and more than 120 schools. He had two sons, Harry and Armand Doctorate. Koch, with the latter joining the firm in the 1890s and helping with the design of the city hall.