The explosion in the opening scene is the infamous 16th Street Baptist Church bombing, which occurred in Birmingham, Alabama on September 15, 1963. The 4 young girls killed in the bombing were Addie Mae Collins, Denise McNair, Carole Robertson, and Cynthia Wesley.
Tim Roth grew up during the Civil Rights Era. He said he remembers George Wallace, thought of him as a "monster," and was "amazed at what was coming out of his mouth."
David Oyelowo's last scene to be filmed was the Nobel Peace Prize acceptance speech. He immediately broke down into tears after wrapping the scene, to enthusiastic applause from extras and crew.
Lee Daniels was originally set to direct. The original cast included Hugh Jackman as Sheriff Jim Clark, Liam Neeson as Lyndon B. Johnson, Robert De Niro as segregationist governor George Wallace, Cedric The Entertainer as minister and activist Ralph Abernathy, and Lenny Kravitz as activist Andrew Young. David Oyelowo was attached to star as Martin Luther King Jr. When Ava DuVernay took over as director, Oyelowo was the only casting decision she didn't change.
The Martin Luther King Jr. estate had already licensed the film rights for his civil rights speeches to DreamWorks and Warner Brothers for a yet to be produced biopic. For this film, Ava DuVernay wrote new variations of those speeches.