What was the root cause of factionalism among american indian nations after the civil war? a. dissatisfaction with the terms of treaties forced upon the american indian nations by the union b. concern with the growing movement of american indian youths who wanted to become westernized c. conflict between those who wanted to live in an autocratic government and those who desired a democratic government d. lingering resentment of the plains indian tribes who were allied with the union during the civil war