The Underground Railroad was a system of safe houses and secret routes that helped runaway slaves escape to freedom in Canada, Mexico, and elsewhere outside of the United States. Before the Civil War, abolitionists, free blacks, and other allies aided the escape of more than 100,000 slaves along the Underground Railroad. Although slavery was never legal in Ohio, the Fugitive Slave Act of 1850 made aiding escaped slaves a crime. Rev. Rankin stated in his autobiography that more than 2,000 slaves passed through their farm, a vital station that made the Rankins among Ohio's earliest and most active conductors on the Underground Railroad. John Parker said, "Ripley was the real terminus of the Underground Railroad."