Because of new union laws, producers were forced to use regular screen extras without stunt experience. In the opening days of shooting 80 were injured and 3 were killed. The filming of the "Last Stand" sequence from this movie involved some 200 horsemen charging around in pretend battle and was so dangerous that one day during filming Anthony Quinn, who played Crazy Horse, arranged as a gag for a hearse to show up at the filming location.
The highest regular Army rank attained by Winfield Scott was actually Major General. Lieutenant General was a brevet (temporary) rank. The First regular Lieutenant General would be Ulysses S. Grant, promoted to the rank in March of 1864. General Scott was also one of three veterans of the War of 1812 still listed in the rolls of the regular Army at the start of the Civil War.
According to 'The Guinness Book of Movie Facts and Feats' a total of three men were killed during the cavalry charge scene. Bill Mead's horse tripped while riding alongside Errol Flynn. As he was going down, the stuntman had the presence of mind to throw his sword forward to avoid it, but bad luck caused the hilt to get stuck in the ground and Mead fell on it, impaling himself.
In the montage of battle scenes which show the Seventh Cavalry taming the frontier when they operated out of Fort Lincoln are several shots of them which will be repeated during the Little Big Horn battle.