In the 1800s, some politicians wanted american indians to adopt white culture. this idea was called

The cultural assimilation of Native Americans was an assimilation effort by the United States to transform Native American culture to European–American culture between the years of 1790–1920.[1][2] George Washington and Henry Knox were first to propose, in an American context, the cultural transformation of Native Americans.[3] They formulated a policy to encourage the "civilizing" process.[2] With increased waves of immigration from Europe, there was growing public support for education to encourage a standard set of cultural values and practices to be held in common by the majority of citizens. Education was viewed as the primary method in the acculturation process for minorities.

African americans at the time just came out of slavery and needed money to provide for there families. so they joined for the money mainly.