Continuity mistake: There are seven Wharvey Gals. Three on the stage singing, three with the wife, and one that she's holding. One of the girls even says that there are seven of them. Yet in the end, when Everett and his wife are walking down the street, there are only six. One that she is carrying, and five following.
Trivia: George Clooney (Everett) was going to sing the song "Man of Constant Sorrow" for the film but it turned out that he was rather awful, so he ended up lip-synching the songs instead. He said "I'm not my aunt [referring to the late singer/actress Rosemary Clooney, best known for her role in "A White Christmas" (1954)]. I decided it would be easier to just do a passionate lip-sync." He was so nervous that the tapes of his singing would get out that he returned to the studio to make sure all of the evidence had been erased. The musical director of the film confirmed this but said "George is a very good singer but that style of music is very difficult and one almost has to grow up singing it in order to sing it convincingly. George did a really good version of the tune but it wasn't as good as he wanted."
Question: In the KKK scene, Homer Stokes says "The color guard is colored." Did he mean this literally, like Everett was a black man, or did he mean that he was white (unlikely because John Goodman is white and so is he), or is he mistaking Everett for a black man because of his dirty face?
Answer: He mistook Everett for a black man because of his dirty face. It's the only way the line makes sense.
Question: The only way that the valley could be flooded by rampaging water is that a dam was broken up river. Otherwise the water rises very slowly. Does the movie explain this? If so I missed it. In which way was that river flooded?
Answer: Probably they have dismantled the coffer dam that was used while constructing the main dam. Hence, the flooding.
Question: The scene when the Ku Klux Klan are assembling is very similar to the scene in "The Wizard of Oz", when the scarecrow, the tin man and the cowardly lion sneak into the witch's castle. The marching music, the disguises and the way they enter the procession are almost identical. Was this intentional?
Answer: Yes, it was.