[MeganC]

The thing was that those indians were trying to get into Canada. Why he, or anyone, wanted to stop them makes no sense. Why not just let them go and be Canada’s problem?

[PzLdr]

The Indians WERE NOT trying to get into Canada. That came later, wehn the Army campaigned against them in the winter. When they left the encampmnet at the Little Big Horn, the Sioux, Cheyenne and Arapaho rode south and southeast.

[Michael.SF.]

I am not sure where the idea that those who attacked Custer were fleeing to Canada, I think you may be confusing them with the Nez Perce.