Frederick Douglass (born Frederick Augustus Washington Bailey, February 1818 – February 20, 1895) was an American social reformer, orator, writer and statesman. After escaping from slavery, he became a leader of the abolitionist movement, gaining note for his dazzling oratory and incisive antislavery writing. He stood as a living counter-example to slaveholders' arguments that slaves did not have the intellectual capacity to function as independent American citizens. Many Northerners also found it hard to believe that such a great orator had been a slave.
http://en.wikipedia.org/wiki/Frederick_Douglass
John Brown (May 9, 1800 – December 2, 1859) was a revolutionary abolitionist in the United States, who advocated and practiced armed insurrection as a means to abolish slavery for good. He led the Pottawatomie Massacre during which five men were killed in 1856 in Bleeding Kansas and made his name in the unsuccessful raid at Harpers Ferry in 1859. Later that year he was tried and executed for treason against the state of Virginia, murder, and conspiracy. Brown has been called "the most controversial of all 19th-century Americans"and "America's first domestic terrorist."
http://en.wikipedia.org/wiki/John_Brown_(abolitionist)