|The U.S. has a bad habit of colonizing an area, then turning a band of settlements into a whole mess of em, pissing everyone else off in the process.|
The U.S. started doing that in Texas (end eventually succeeded), pissing mexico off... did that with Oregon too, neither the Natives nor the British were too happy about that. It was supposed to be 'joint settlement' but the U.S. outsettled everyone else. Today, Oregon and Texas are both part of the U.S.
About Mexico, the standard of living there is a bit low for my preference as far as I've heard.