Why did u.s. policies toward native americans in this era result to so much violence? why did armed struggle continue as late as 1890, despite the u.s. "peace policy" that was proclaimed in the 1970s?

They tried to assimilate indians into the white ways. Through the dawes severalty act in 1887, it broke up tribal land holding and gave indians individual ownership of land. In their territory the government took over 15 million acres where native people lost 66% of allotted lands.

U have a better explanation ? or no bc i u didnt really put alot of info