John Brown came up in the Dutch classic standard Amerika by Jacques Presser on the United States. Brown was described as a fighter of slavery in the nineteenth century but long before the Civil War. One might say he was ahead of his time. He was also described as a deeply religious man, setting fire to all and each in his way of his Crusade against slavery, all in the name of God's glory. Quite a remarkable figure. In the book there is a picture by Steuart Curry called Tragic Prelude in which Brown is depicted being... at it, let's say. For some reason I can't help but hear him say "ooooohhhh!" in a Paul Roberson kind of way.
By the way, if Brown was fighting battles before 1860 and his opponents were already waving a Confederate flag around like they do in the painting, then they were just about as ahead of their time as Brown.