What were the debates on the treatment of Native Americans and the justifications for subjugating them (and Africans?

The answer is stated below.

Explanation:

The racist ideology was used to rule over the Africans and Native Indians as the color of white skin was believed to superior and therefore their rule over these inferior people was to protect them and make them civilized. The manifest of destiny is the ideology that made it the destiny of the white settlers to spread the modern civilized culture of democracy to the entire continent.