Ken Burns' 'Muhammad Ali' documentary, premiering September 19 on PBS, is as thorough as it is fascinating.

Muhammad Ali, born Cassius Clay on Jan. 17, 1942, is regarded as one of the top professional boxers of all time. He was an activist who spent his life fighting for and enacting change.

Floating and stinging as it explores the boxing icon’s life inside the ring and out, “Muhammad Ali” is another epic Ken Burns-produced dive into the life of an influential 20th-century figure.

Nico Ali Walsh works out at Gleason’s Gym, where his grandfather often trained when he came to New York. Robert Sabo Before arriving in Brooklyn, Nico got a behind-the-scenes MSG tour, seeing ...

The making of a champion: Ali’s early years American Heavyweight boxer, Cassius Clay (later Muhammad Ali, 1942 – 2016), making a fist as he lies on his hotel bed, London, 27th May 1963.

Foreman attended Ali's memorial and funeral service when Ali died in 2016. But the relationship got off to a rocky start in 1974 leading up to "The Rumble in the Jungle,'' their fight in Zaire.