The correct answer is Mexico.
Because of Mexico and their gulf of Mexico, the United States cannot control the entire gulf area. If the area changed hands and went to the United States, they could unite the two gulfs and have a huge control over the land and the ports in the new world. However, that's probably never going to happen so it stays this way for now.
The trend that has been true in the United States is that minorities are growing fast.
He insisted that his people make peace with the native people. This way they could avoid conflict.