The first scene in Brando's childhood takes place in Kansas 1932. However at that time he and his parents were living in Evanston, Illinois.
The movie portrays Marlon Brando to have only 2 children, Christian and Cheyenne. In real life he had 11 children, most of them being illegitimate.
The entry of the Pennsylvania Station which Brando exits shows the current design on it rather than the one from 1943.