The movie, inspired by a true story about an all-black debate team at Wiley College in Texas during the 1930s, was produced by Winfrey's company and is Washington's second try at directing.
Washington, who also stars in the movie, said Winfrey was available for help on the project, which he called "her baby," if needed but "really stayed away."
"She saw the first cut in September, and she said she loved it," Washington told the New York Post. "She was crying and the whole business. I was like, 'Phew.' It could have been a bad night."