When Chuck & Carol stop for gas, a torn movie poster is prominently displayed on the wall of the station. Although the title and the name of the players have been ripped off, it's quite obviously Tomorrow Is Forever with the images of its three stars, Claudette Colbert, George Brent, and Orson Welles, easily identifiable; this film was not actually produced until 12 years later, in 1945, and released in 1946.
When Chuck drives the black workers to their new TVA-built homes, a white car can be seen parked in the distance which appears to be a 1949 or 1950 Ford, but which in any case is plainly not a vehicle that would have existed in 1933, when the film is set.
At the very end of the movie, as Chuck and his new family are departing the movie story's location and are flying over and looking down on the now newly flooded island that had been his new wife's old home. This flooded island would actually have to be on the reservoir side of the damn when they closed the dam's flood gates that would cause the reservoir's waters to rise. However, in the very next shot their plane is shown approaching the damn from over the un-flooded river side. The reservoir where the flooded old home island they were just looking down on would in reality have to be on the other side of the damn they are now shown to be flying toward and over.
The last part of the movie shows Fontana Dam. For some reason this picture has been reversed - the observation area is actually on the right of the dam not the left (creek side of dam). Also the last picture is not this dam. Fontana Dam is built straight where the last dam is curved. The curved dam is Calderwood Dam, the 2nd dam down the Little Tennessee River from Fontana Dam.