Factual error: In the scene when Michael visits his father in the hospital in 1945 there's a NYC Fire Dept. sign on the wall with the name of the Commissioner, Robert O. Lowery, who was commissioner from 1966 to 1973.
Factual error: Throughout the end there is fire everywhere. All of that fire would consume any oxygen that was in the rooms and fill the rooms with heavy black smoke. They are walking and climbing everywhere without the effects that the smoke and lack of oxygen would have caused.
Factual error: The colt .45 that Telly Savalas uses didn't come into use until 1911 (the film's set in 1909).
Factual error: In the beginning of the film the setting is very late summer or early fall as evidenced by the reference to getting back home in time to watch the football game on Sunday. Yet the deer that Ed shoots at is in the early stages of antler growth that appears to be more typical of late spring or early summer. The deer also appears to be some exotic species, not one of the whitetails that are native to Georgia.
Factual error: When the girl gets stabbed in the back, the blood should not come out that fast or go everywhere.