Kansas abolitionist John Brown seizes the attention in the middle of John Steuart Curry's famous "Tragic Prelude" mural at the Kansas Statehouse. (Photo by Dave Kendall)On the ground floor of the Kansas Statehouse, you can find a plaque bearing the grim visage of abolitionist John Brown. Alongside his face are printed these words: I, John Brown, am quite certain that the crimes of this guilty land will never be purged away but with blood. Two f…