Burgoyne had his troops carry a lot of baggage which slowed them down while the Americans sabotaged their path.
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.
