Born in Danville, Ohio, Sapp attended the public schools and Martinsburg Academy.

After studying law, he was admitted to the bar in 1850 and commenced practice in Mount Vernon, Ohio.

He was an unsuccessful candidate for prosecuting attorney of Knox County, Ohio in 1850, but was elected four years later (in 1854) and re-elected in 1856.

He was a candidate for renomination in 1880 but was defeated by another former lieutenant colonel of a cavalry during the Civil War, William Peters Hepburn, after 346 ballots.

This article incorporates public domain material from the Biographical Directory of the United States Congress