Benjamin Bradley was born into enslavement around 1830 in Maryland. He “was put to work in a printing office and at the age of 16 began working with scrap he found, modeling it into a small ship. Eventually, with an intuitiveness that seemed far beyond him, he improved on his creation until he had built a working steam engine, made from a piece of a gun-barrel, pewter, pieces of round steel and some nearby junk,” according to blackinventor.com.
Bradley’s ingenuity earned him a job at the Annapolis Naval Academy, where he was a classroom assistant in the science department. While there, he developed a steam engine large enough to drive the first steam-powered warship at 16 knots for warships in the 1840s. He later sold the invention and bought his and his family’s freedom.