With all the problems the Sioux had at that time it was general believed they were instigated to go to war by Confederate agents working through tribes in Canada.
They DID have lots of tribesmen instigating the other tribes all over the west.
The tribes that made or were negotiating treaties with the Confederacy.
Cherokees, Creeks, Choctaws, Comanches, Wachitas, Kiowas, Pottawattamies, Chickasaws, Osages,
Seminoles, Senecas, Shawnees, Quawpaws.
The South also had Indian agents operating all throughout the High Plains and mountain region stirring up other tribes such as the Sioux, Cheyenne, Arapaho, Navajo and Apaches to make war on the Union at that time.
Their traditional enemies, Pawnee, Kaw, Osage (well, part of them) remained loyal to the Union.
“There is little doubt that the recent outbreak in the Northwest (Minnesota Uprising) has resulted from the efforts of secession agents operating through Canadian Indians and fur-traders.”—Mr Giddings, US Counsul-general in Canada
“With all the problems the Sioux had at that time it was general believed they were instigated to go to war by Confederate agents working through tribes in Canada.”
Propaganda.