Brown was an abolitionist with strong religious convictions. He felt that violence was necessary to end American slavery, since decades of peaceful efforts had failed. In May 1856, Brown and his sons killed five supporters of slavery in the Pottawatomie massacre. Brown then commanded anti-slavery forces at the Battle of Black Jack and the Battle of Osawatomie. Brown was eventually executed by the government after his failed attempt to incite a slave rebellion at Harpers Ferry in 1859.