While set in Louisiana, parts of the film were shot at the Virginia State Capitol, in Richmond. The Seal of the Commonwealth of Virginia is clearly visible on the backs of the legislators' desk chairs.
There's a scene showing Huey attending the funeral of his Uncle Albert, but according to online genealogy sources, his dad's brother who had that name actually died in 1940 (too late for the period shown in the film).
Huey is shown campaigning for railroad commissioner in 1919, according to the information onscreen, although the election happened in November 1918. But the timing of Rose's pregnancy is right: their son Russell was born just days before the vote, and used to joke that in all the excitement, his parents forgot to buy diapers for him.