Oprah Explains Why 'Selma' May be Her Most Important Movie Yet

ETONLINE

Oprah gave ET's Nancy O'Dell a behind the scenes look at her new movie Selma.

Oprah Winfrey gave ET's Nancy O'Dell a behind the scenes look at her new movie -- the Martin Luther King Jr. biopic Selma.

Oprah produces and stars in Selma which follows a crucial time in MLK's life when black marchers attempted to walk from Selma, Alabama to Montgomery in order to obtain voting rights in 1965. The journey took three attempts due to police resistance. Brad Pitt is also producing the film via his Plan B production company, which also produced 12 Years a Slave.

NEWS: Oprah Reveals Who's Playing MLK in Selma

In the movie, Oprah plays little-known activist Annie Lee Cooper who became a catalyst for change during the Voting Rights Movement.

"She was a woman who actually tried to vote four or five times, was not given the right to vote, and when the sheriff forbid everybody from coming down to the courthouse, she ended up having a big fight," Oprah told Nancy.

Oprah's The Butler co-star David Oyelowo stars as MLK, and he told Nancy how Oprah played a part in him getting the role.

"She saw an audition tape of me as Martin Luther King and she became obsessed," said David. "From that moment on, I would get phone calls from far flung parts of the planet of people saying, 'I spoke to so and so, we are going to try to make this happen. This is happening!' I was just like, 'Oh, okay!'"

Watch the video for exclusive shots of the movie's recreation of that famous march to Montgomery. Selma opens in limited release Christmas Day.