Factual error: The movie takes place in the early 20th century (1910s or 1920s or so). When Dean and Jerry are riding in a RR cattle car with its doors open you can clearly see parked automobiles from the 1950s through the open door of the train car.
Factual error: The Welsh Guards parading at the start of the film weren't formed until 1915. The film is set in 1872.