When Billy picks up the pups from the train station, they are about eight weeks old, but in the montage following showing him with the pups on his trip home, in the shot with the pups frolicking in the camp the next morning, they appear to be about three months old. Then, when he gets home and shows them to his parents, they are again eight weeks old.
The tree that Billy cuts down is referred to as a sycamore but the tree he is shown cutting is not a sycamore.
Movie is set in 1935, but at 59:03, Base Player on right wearing Digital Watch when movie is set in 1935.
When Billy is given the trophy for catching the most raccoons, the camera pans the crowd and a little girl is shown (briefly) smiling, wearing braces on her teeth. Braces weren't invented yet during the period in which the movie takes place.
At the Ozark Coonhound Championship the banner says that the year is 1937, but earlier panning across the grounds there are trucks from the late 1940s- early '50s.