Born Cassius Marcellus Clay on January 17, 1942, in Louisville, Kentucky, Ali started boxing at age 12 — and ultimately became known for much more than just his successful boxing career.

Truth is, Ali’s father—Cassius Marcellus Clay, Sr.—was named after a Kentucky slave owner turned abolitionist. The original Cassius Marcellus Clay (1810-1903), nicknamed Cash, was the son of ...