Honest, I really wanted to like this more than I did. Salad family trivia: It was the only Best Picture Oscar nominee we hadn't seen from last year.
It starts out recreating a horrible moment in history: the 1963 Birmingham church bombing that killed four black girls, aged 11-14. And then a dramatization of Annie Lee Cooper's—Oprah!—failed attempt to register to vote at the Selma courthouse. (She successfully recites the preamble to the Constitution. She knows there are 67 county judges in Alabama. But—oops!—she can't name them. Sorry, Annie.)
Into this steps Martin Luther King Jr. and various less-famous activists from the Southern Christian Leadership Council (SCLC) and the Student Non-Violent Coordinating Committee (SNCC). It's decided to use Selma as a symbol to pressure President Lyndon Johnson and the US Congress to pass Federal voting rights legislation. Over the period of a few months this gives rise to a massive violent confrontation at the Edmund Pettus Bridge, in addition to the deaths of other protesters.
What's good: the main black actors do an uncanny job of recreating their characters. David Oyelowo as Dr. King and Carmen Ejogo are especially good. (In contrast, Tom Wilkinson and Eli Roth are never that convincing as LBJ and George Wallace, respectively.)
Not so good: the characters tend to sermonize at points when, in real life, they would be speaking more normally. And the movie takes pretty unexcusable liberties with actual events. It's important to get things right.