PHILADELPHIA (AP) — Retired boxing champ Muhammad Ali was known as "The Greatest" inside the ring. But some say the moniker has been even more fitting in the years since he hung up his gloves.

Ali came to Philadelphia on Thursday to receive the Liberty Medal for his longtime role as a heavyweight for humanitarian causes, civil rights and religious freedom. Among those celebrating his latest honor at the National Constitution Center were former NBA star Dikembe Mutombo and Joe Louis Barrow II, the son of boxer Joe Louis.