Billy and Bobby Mauch were identical twins. When Billy was cast in "Anthony Adverse," Bobby was to be his stand-in for unimportant scenes. Once the film was completed, however, the twins revealed to director Mervyn LeRoy that that had taken turns playing the lead role throughout the movie, confident that no one would notice. They are said to have played the same trick during the filming of "The White Angel," where Billy again was cast as the lead. The only noticeable difference between them is that Billy is left-handed, and Bobby is right-handed.

                                        --- edited from "The Moving Picture Boy," by John Holmstrom