The responsibility to confirm or approve presidential appointments is an example of the principle of

Approval by the senate of presidential appointments is an example of the principle of checks and balances. Appointments by the president are of great importance: the people appointed by the president, from cabinet members to justices, are put in positions of great power without being elected by the people. The need to be confirmed by the Senate helps to put a check on this power. 

They had strained relationships with colonists but good relationships with american indians