★ ★ ★ ½

More often than not, cradle-to-the-grave biopics are sprawling movies that lack focus and end up doing a disservice to the importance of their subjects. Ava DuVernay’s Selma avoids that pitfall altogether by focusing on just a few crucial months in the life of Martin Luther King Jr. In so doing, she’s created both an excellent history lesson and a fully realized psychological portrait of a transformative 20th century crusader.

David Oyelowo stars as King, who, as the film opens in 1965, is pushing President Lyndon Johnson (Tom Wilkinson) to address the voting-rights problems blacks are experiencing throughout the South. He details how systematic efforts to keep black people from the polls result in continued poverty, and represent a failure to live up to the country’s standards. Johnson is sympathetic, but he has other political battles to fight and refuses to help to the degree King would like. In response, King and his fellow civil-rights leaders plan a peaceful march from Selma, AL, to the state capital of Montgomery in order to take their demands to Governor George Wallace (Tim Roth), knowing full well that if the news cameras see people being abused by officials, Johnson will be goaded into taking action.

The first thing that will jump out at anyone who sees Selma is Oyelowo, a talented actor who gets his biggest role to date here. He gives a marvelous performance that doesn’t so much impersonate the Nobel Peace Prize winner as embody his public resolve and steadfast righteousness. All the while, the actor makes sure we realize that King understands the toll his actions are taking on his marriage and his family. He’s inspirational not because of the odds he overcomes, but because of the sacrifices he makes to succeed.

DuVernay shows a talent for both large-scale scenes and intimate conversations. The centerpiece of the movie, the march to Montgomery that is violently broken up by local law enforcement, is brutal without being sensationalistic. The sequence is violent and epic, but much of its power is derived from the fact that so many of the people we see suffer are individuals we’ve come to know and care about. The film smartly personalizes the civil-rights battle for the audience.

Additionally, the scenes in which we see King away from the cameras and the crowds, including a memorable conversation with one of his closest collaborators while they sit in a jail cell, help humanize the man. He’s shown to be a savvy speaker who could move others with his fiery oratory, but just as importantly, we see how he could inspire people in one-on-one interactions, earning loyalty with his truthfulness, intelligence, and fierce sense of right and wrong.

Selma is the kind of movie that will be shown by smart high-school teachers, and that’s not meant to sound like a dismissal. For all of the weight of history it carries, it’s the rare biopic that actually works as both a personal story and an exploration of America’s past.