US has been pretty open to immigration at some points, and relatively closed at others. For the most of last 250 years, it has been mostly closed to non-white immigration, for example. With the exception of black Americans, the current racial and ethnic diversity in the US is a rather recent phenomenon.

The US had no laws restricting immigration, period, until 1882. The national origin quota system didn't exist at all until the 1920s.

Ethnic diversity has been part of the fabric of the US since before it was a country. Per census figures, the percentage of the population that wasn't born in the US was higher in 1910 that in it today.

And, of course, the very concept of "immigrant from Europe or descended from them => white" is a lot more recent than 250 years ago. The Irish weren't considered "white" when they arrived en masse after 1820. Italians, Greeks, and various Slavs also weren't considered "white" when they arrived in the early 20th century. Suspicion of divided loyalties for a Catholic president was a big issue in the 1960 elections (JFK vs Nixon).

> The US had no laws restricting immigration, period, until 1882.

Yes, but it had Naturalization Act of 1790 that restricted naturalization only to white people. It wasn’t an immigration restriction, to be sure, but very few non-whites immigrated to US anyway (other than the forced immigration of black slaves), rendering the issue moot.

> And, of course, the very concept of "immigrant from Europe or descended from them => white" is a lot more recent than 250 years ago. The Irish weren't considered "white" when they arrived en masse after 1820. Italians, Greeks, and various Slavs also weren't considered "white" when they arrived in the early 20th century.

This is very much false and ahistorical. Many of them weren’t liked by then-locals, and in fact we’re often discriminated against, but at no point they were seriously considered non-white. There have been some activists recently claiming otherwise, but it has been based on very weak historical grounds. Consider, for example, that after the Ozawa case, at no point the question of Irish or Slavs’ whiteness ever came up on a court docket, while it did for Arabs, Syrians, Filipinos, and many others: https://academic.udayton.edu/race/01race/White05.htm

> Suspicion of divided loyalties for a Catholic president was a big issue in the 1960 elections (JFK vs Nixon).

There was, but, as it turns out, Catholicism is not a race.

Tons of people hated the Irish for immigrating to the US. There are plenty of example of the hatred of Italians and Irish in the turn of the last century. Watch Gangs of New York for a taste of the bigotry.

Irish and Italians are lumped into White and now we have comments like yours. Most of the people in the US are from Europe so of course they favored family, friends, and countrymen coming over.

I don’t understand the point of “white” and race in this conversation. In fact the concept of “white” may be a rather recent phenomenon.