The film isn't bad although they changed some historical facts. But they did mostly stick to what is known and they didn't portray Jesse James as some sort of good guy. The murderous Jesse James often got portrayed as some type of Robin Hood in the era and after. However, the Assassination of Jesse James by the Coward Robert Ford is a brilliant film about the same events with more historical accuracy, better acting and amazing cinematography.
Review of I Shot Jesse James
