Factual error: When Lt. Dunbar is preparing for his meeting with the Indians, you can see the rubber sole of his boot as he is putting it on. There is also a stamped logo on the boot heel. Rubber bottomed boots did not exist during the Civil War.
Suggested correction: True enough officially, but it often happened during war or in remote areas or in this case Both, unconvential materials would be used in improvised solutions.
Continuity mistake: The Civil War battle scene has trees already turning fall colors, and the cornfield is already showing frost damage with dying top leaves. The likely timing for scenery such as this would be about mid to late September. There wouldn't be enough time for Dunbar's leg to heal, then travel 1000 miles west, then establish rapport with the Sioux, then go on a buffalo hunt, then move to winter quarters before snow flies.
Suggested correction: Maybe he recovered over fall and winter, then traveled west in spring?
Dunbar tells the Army soldiers that have him captured that he arrived at the fort in April.
