Factual error: The time period of the film is 1932. In the opening title sequence, you see someone playing with Crayola Crayons (I assume it's Scout). One of the Crayons is labeled "Melon". Binney & Smith didn't sell the Melon colored crayon until 1949. Crayons produced from 1903 to 1948 sold for a nickel and contained only eight colors: red, orange, yellow, green, blue, violet, brown, and black.
Factual error: Cape Fear the town, the river and the cape, are all in North Carolina. The civil-rights-type lawyer tells Bowden that a committee sitting in the state capital will see that he never tries another case in "this state." That committee turns out to be in Atlanta. The Atlanta trip is a vital part of the plot - the word "Atlanta" occurs about a dozen times in the script.