How Benjamin Bradley sold his history-changing invention to purchase his freedom

Benjamin Bradley shocked his cohorts and owner when he built a steam engine out of a gun barrel, steel and pewter, among other materials.

Awed by his brilliance, his owner arranged for him to serve as an apprentice at the Department of Natural and Experimental Philosophy at the Naval Academy in Annapolis, Maryland. Bradley had actually shown interest in mechanical engineering at the young age of 16.

He showed a lot of promise at the Naval Academy and was allowed to assist with science experiments involving chemical gases. While at the Academy, he built a steam engine and sold it to the “Midshipmen”, according to the African-American Registry. He used the proceeds and the monies he saved from his service at the academy to build a larger steam that could propel “the first sloop-of-war (a small warship carrying guns on one deck) at the rate of 16 knots an hour,” BlackPast wrote.

Bradley knew that his status as a slave would make it impossible for him to patent his invention because of the state laws. So he sold the model engine to a colleague at the Naval Academy and built the first steam engine that could power a warship. He sold this invention and used the proceeds including monies given to him by professors at the academy to purchase his freedom at $1000.

Bradley gained his freedom from his owner, John T. Hammond, on September 30, 1859, in Anne Arundel, Maryland, according to Maryland State Manumission. He was later employed as an instructor by the Philosophical Department at the Naval Academy in 1864 when the Academy relocated to Newport, Rhode Island during the American Civil War. Now employed as a free person, he worked under Prof. A.W. Smith.

Bradley turned his energies to building small steam engines and lived up to his dream of being a guru in the mechanical space. He was acknowledged for his design and construction of a “miniature steam engine and boiler about 6-fly power.” 

Born in March 1836 in Anne Arundel County, Maryland, Bradley learned how to read and write from his owner’s children. He worked at a printing company in his formative years. In 1900, he was captured by census officials as being 64 years old and living in Mashpee, Massachusetts with his job description as a philosophical lecturer. He was married to Gertrude Boardley for 19 years and they had three children, per the census. Bradley passed away in 1904 and was buried at the Mashpee Town Cemetery in Massachusetts.