I appreciate you and thank you for your perspectives, xipotec. Just a technical difficulty but this country was actually founded on genocide. Immigration nearly wiped out a whole population. And those who survived and didn't conform to the "new values" were sent to boarding school/killed. I think the basis of immigration anxiety right now, with many Americans, comes from this knowledge and fears of this repeating to some extent. #AmericanHistory
America has greatly, positively changed the world overall. But it's beginnings were not some sort of dream sequence like elementary teachers tell you during Thanksgiving time. Let's not continue the fallacy that the country was built on the wonderful idea of immigration.
What you're describing sounds more like an invasion, than immigration . Immigration involves a legal process, in which foreigners have to make the necessary applications, and fit certain criteria, for a country to accept them. The early Europeans didn't do that when they first arrived on the American continent.
As for modern times, not all immigration is helpful, but not all of it is detrimental to a society, either.