Caption reads "Opening in back porch of house, located at 408 East Sixth Street, Cincinnati, Ohio, where slaves are said to have been stored awaiting shipment during slavery days. Photo by Writers' Projects. District #2. 11-12-36." The Underground Railroad was a system of safe houses and hiding places that helped runaway slaves escape to freedom in Canada, Mexico, and elsewhere outside of the United States. White and African-American "conductors" served as guides from place to place for runaway slaves. It remains unclear when the Underground Railroad began, but members of the Society of Friends, who were also known as the Quakers, were actively assisting runaway slaves as early as the 1780s. Some people living in Ohio began to help ru...