Jonathan Walker was a white Massachusetts sea captain and a staunch abolitionist.
In 1844, Walker attempted to smuggle seven freedom seekers from Pensacola, Florida to the Bahamas. His boat was captured, and the freedom seekers were returned to their owners.
Walker was jailed and branded on his right hand with "SS" for "slave stealer." Walker served eight months in jail and was forced to compensate slaveholders for damages for lost labor. He later travelled the north telling his story and displaying his hand. His branding showed many the horrors of slavery up-close. Walker was the only man ever to have been branded by federal order in the United States.