He was the slave who was given a commission and command of the USS Planter after "stealing" it from the Union Navy. He would go on to become a member of the U.S. Congress.

The person you are referring to is Robert Smalls. He was a former slave who served as a pilot on the USS Planter during the Civil War. In May 1862, Smalls and a group of fellow slaves commandeered the Planter and sailed it past Confederate defenses to surrender to Union forces. Smalls' heroism earned him a commission as a lieutenant in the Union Navy, and he later served in the South Carolina state legislature and the U.S. Congress.