Among Oshkosh's landmark structures is the six-story office building built by Ganther for Firstar Bank, formerly First Wisconsin National Bank, at 111 North Main Street in downtown Oshkosh. The glass and concrete structure is a true "Class-A" office building designed and built to stand the test of time. The building is now home to U.S. Bank and Dempsey, Williamson, Kelly and Hertel LLP - one of Oshkosh's oldest law firms.