Schoepf was born in Poland and came to the United States in 1851. While working as a porter in a Washington hotel, he met Joseph Holt, then the commissioner of patents. Schoepf followed Holt to the War Department, where he was given a field command in 1861, brigadier general of volunteers. He served in the Army of the Ohio until he asked to be relieved and was then given command of the federal prison camp at Fort Delaware on Pea Patch Island, near New Castle. Although located in a marshy area and grossly overcrowded, the number of deaths per 1,000 prisoners was somewhat less than other prison camps and Gen. Schoepf is credited with being an efficient administrator of the camp.