The US told the world in the 19th century that South America was not to meddled with, except by the US. I fully blame America for structural failures in South America that trigger illegal immigration. The US refused to enshrine stable countries that prevented their best and brightest from leaving.

Yes, yes you do. Having 10 mil illegal immigrants is as much a result of American policy choices as having rapist in president's office

For the majority of the existence of the USA there were no such thing as a border. You could immigrate simply by traveling to the USA.