Michael Caine's first attempt at an "American" accent. Vivien Leigh told him to memorize the phrase "four-door Ford".
Michael Caine told in his biography that, aware of the difficulties in working with Otto Preminger because of his nasty temper with technicians and actors, Caine told Preminger that he was a shy man, very sensitive; if anyone shouted at him, he would burst into tears for the rest of the day and would remain in his dressing room. Preminger never bothered Caine nor shouted at him in any way.
Footage from this movie of a young Sir Michael Caine was used in Austin Powers in Goldmember (2002).
Because of the racial nature of the film, and the fact that black and white actors worked together--a fact that was not popular in the South at that time--the cast and crew had to be protected by heavily armed state police. They received death threats from the Ku Klux Klan, and their car tires were slashed.