What happened to the southeastern tribes?

Theodore roosevelt beloved that the only checks on presidential power were

How might the first nations have reacted when they saw that the europeans were moving onto their lands and disrupting their way of life? (this was when the europeans came to canada and tried to claim land to themselves)

The system of checks and balances was designed for what purpose? fear of strong state power to keep power out of one branch to appease the southern states to allow the judicial branch to have equal power