The series is told from the point of view of Henry Shackleford (Joshua Caleb Johnson), a fictional enslaved boy, who is part of John Brown (Ethan Hawke) motley crew of abolitionist soldiers during the time of Bleeding Kansas, eventually participating in the famous 1859 raid on the Federal Armory at Harpers Ferry, Virginia (since 1863, West Virginia). Brown's raid failed to initiate a slave revolt as he intended, but it was one of the instigating events that started the American Civil War.