4. Lewis Latimer
Lewis Howard Latimer was an African-American inventor and slave. After escaping from a plantation with his wife Rebecca, Latimer arrived to Trenton. Unfortunately, the slave master tracked him and his case came to the attention of an abolitionist, William Lloyd Garrison. He was able to gather $400 and paid Gray for Latimer’s freedom. Latimer served in the US Navy during the Civil War and honorably discharged after the war ended. He was also known for his technical drawing and Alexander Graham Bell asked him to draw for the famous telephone patent. With Charles W Brown, Latimer co-patented an improved toiled system for railroad cars and later, an improved method for manufacturing light bulbs filaments.