EVEN IF HIS PRIME was before your time, you know the broad strokes of Muhammad Ali: One of the greatest boxing champions of all time, conscientious objector to the Vietnam War, figure of the civil rights movement. He lit the Olympic torch in 1996. He was awarded the Presidential Medal of Freedom by George W. Bush in 2005, footage of which is included early on in Bill Siegel's (The Weather Underground) new documentary, The Trials of Muhammad Ali. As the war president attempts joviality, Ali stares passively into the cameras without a flicker of excitement.

The irony in this event is elaborated in Siegel's film, a balanced account of an Ali most Americans don't recall. His early success was quickly threatened by his choice to become a member of the Nation of Islam (prompting his name change from Cassius Clay). A famous ham, Ali seemed to take as much pleasure in boasting as he did fighting, but once his polarizing beliefs—which, at the time, called for racial segregation—became a focal point, his interviews with the press got less fun.

When he was drafted into the Vietnam War, the protest movement was still nascent. Rather than getting rallied around by free-loving hippies, Ali was widely despised for his refusal to go to war. He lost his heavyweight title and was banned from the sport while he battled in the courts.

Trials is primarily concerned with these struggles outside of the ring. Weaving archival footage and interviews—including with Ali's wife at the time, Khalilah, his brother Rahaman, and Louis Farrakhan—Siegel examines what it meant for Ali to stand at the confluence of the two defining controversies of '60s and '70s America. Ali's choices weren't yet popular or vindicated, and he risked all he had achieved for the sake of his beliefs. As famous as Ali is, Siegel's personal approach also invites introspection into one's own identity, values, and destiny.