Zachodnia ekspansja: rozwój społeczny i kulturowy

“Hereafter no Indian nation or tribe within the territory of the United States shall be acknowledged or recognized as an independent nation, tribe, or power with whom the United States may contract by treaty. Provided, further, that nothing herein contained shall be construed to invalidate or impair the obligation of any treaty heretofore lawfully made and ratified with any such Indian nation or tribe.”

-Source: excerpt from the Indian Appropriation Act, 1871