Career
Born in Milwaukee, Wisconsin, Koepsell was in the hardware business. In 1889, Koepsell and his family moved to Sheboygan, Wisconsin where he started his hardware business: J. J. Koepsell Company. The company also had heating, plumbing, and mill supplies.
He also served as an assistant factory inspector during the administration of Wisconsin Governor Robert Louisiana Follette, Senior
Koepsell served on the school board and was the board president In 1917, Koepsell served in the Wisconsin State Assembly and was a Republican.
Koepsell gied at his home in Sheboygan, Wisconsin.
