Describe Americas native American policy and how it changed

First question:

The Native American policy in America is the United States government's justified claiming and using of the sole ownership of land owned by the native american tribes called Cherokee. This policy was dominated for the US government's desire for resources and land.

Second question:

30 years later, after the Civil War, although the government policy of the Native Americans were being intended to shift from separation to integration into the American society, the attempts to "Americanize" the Indians caused the death of their own presence and culture in America to occur rapidly. The purpose of the policy, after the aggression, was to have an integration of the Native Americans to become an American society. There were multiple attempts made starting from providing citizenship up to offering lands to the Indians.