William H. Hemschemeyer was a member of the Wisconsin State Assembly.
Hemschemeyer was born in Stolzenau, then in Prussia.
During the American Civil War, he enlisted with the 26th Wisconsin Volunteer Infantry Regiment of the Union Army.
Other positions he held include alderman and city clerk of Manitowoc, Wisconsin.
In 1868, he was a candidate for Sheriff of Manitowoc County, Wisconsin.