Factual error: In the train scene near the start there are vapor trails from modern day jet aircraft in the sky above. (00:06:15)
Factual error: Corporal Woodson (the black soldier on Yellow Hawk's escort detail) should not be present, since in 1892 black cavalrymen could only serve in the segregated 9th and 10th Cavalry Regiments. The unit depicted in the film is the 2nd Cavalry, at the time an all-white regiment.