Emancipation Proclammation, not sure if I spelled it right but that is the answer
The correct answer is: "Write their own constitutions."
In the 19th century the Manifest Destiny was a wide spread belief in America. Most activities that demonstrated the belief were; The Louisiana Purchase, The Alamo, Indian Reservations (Trail of Tears) and so on. The Manifest Destiny was a belief that often caused many problem among allies and enemies.