Why is the separation of government powers a requirement for a society to be free?

In the mid-1800s, how did american indians often react to the us government signing treaties with tribal chiefs to establish reservations? many american indians did not accept the treaties and resisted relocating. many american indians fought for land taken away by the dawes act. many american indians bought land in oklahoma from white settlers. many american indians accepted the treaties and relocated voluntarily.

Which of these belongs to the united states after the spanish american war ?

How did american entry into world war i affect the allied powers?