The entire concept as a nation for over two centuries has been to take in immigrants from everywhere and create a melting pot culture where everyone makes new lives together.

Tell that to the chinese and irish workers doing railroad construction. The native americans that were (and still are!) genocided. All the africans that were brought in as slaves to replace the enslaved native population because it is easier to control foreigners in a strange land than the people that lived there for millenia. Immigration were from the colonizers country (France and England), and other nations were only allowed (or forcibly brought) in for cheap labor.