I have a G-grandfather William Repp, son of Elias Repp. He lived in Menomonie, WI from 1880 to at least 1888 when my grandfather Clinton was born. They moved to Kenosha, WI 1890 something. When his wife died in 1897 my grandfather went to live with his aunt and the family lost track of William. I believe Elias Repp lived in Indiana around 1850, and William may have been born there. Could this be your William?