Frederick Douglass was many things: a gifted writer, a brilliant orator, a shrewd political strategist. But he was most certainly not a pacifist. He welcomed the Civil War as the best means to end slavery and helped two of his sons enlist in the Union army.

Douglass was also a longtime confidant and admirer of John Brown, and well after the lethal Harpers Ferry Raid in October 1859, Douglass continued to pay tribute to the man that he (along with other devotees) called Captain Brown.

None of this is in dispute. Yet what’s largely forgotten — and considerably more controversial — is Douglass’s murky role in the Harpers Ferry assault. A key member of Brown’s army allegedly told authorities that Douglass had broken his promise to join the insurrection. And well into the twentieth century, several of Brown’s immediate descendants, along with a friend from Boston who visited him as he faced execution, echoed this claim.