When Cassius Clay joined the Nation of Islam in 1964 and changed his name to Muhammad Ali he had a straightforward explanation. “Why should I keep my white slavemaster’s name visible and my black ancestors invisible, unknown, unhonored?” Ali asked.

Then, it was more of an abstract concept, a statement against white oppression; Ali did not know much, if anything, about his ancestors or his own family tree. Decades later, though, Ali’s family has made a discovery that appears to shed new light on the boxer’s lineage — where he came from, and also his place American history. Ali, according to his family’s research, is the great-great-great grandson of Archer Alexander, a slave who heroically fought both for his own freedom and against slavery.

Alexander escaped from bondage and surreptitiously fed information to the Union Army during the Civil War. He was later the model for the slave depicted in the Emancipation Memorial, a statue in Lincoln Park, about a mile east of the U.S. Capitol.