I would say perhaps Europeans as a whole have much more experience living in a foreign country than Americans do. But as an American with significant travel experience globally, I have yet to visit a country that is as culturally diverse as America.
But, I have been to Spain, Italy, Greece, and Turkey.
And it was all full off Spaniards, Italians, Greeks, and Turks, respectively.
Colonialism does mean many european countries do count among their ranks people who aren't "native" to europe, but America is a land of immigrants. Full stop.
Sources?
Most of Europe is not very diverse. It took me a while to overcome the culture shock of what is essentially a European monoculture. The most diverse country I encountered in Europe was probably Spain.
What do you mean by "mexican border"? I think you are talking about preconceptions based on the news cycle.
At work in Europe, you will get weird comments if you are not a white person. I never encountered anything like that in the US.
Most ethnic minorities in Europe tend to be more thinly spread out as compared to the US, and there is much more interaction between Whites and racial minorities. This is one of the biggest complaints that I get from Indians about the racial culture in the US, but it's also traditionally famous among Blacks as well. It's based on the traditional mixing of ethnic groups that has been going on for thousands of years - remember even during the Roman Empire and Ancient Greece, there were immigrants from Africa, Middle East and South Asia.
EDIT: This chart on the Non-Hispanic White distribution similarly has Northern America as being more white than Southern America: https://upload.wikimedia.org/wikipedia/commons/5/54/Non-Hisp...
Black people aren't immigrants. They were taken from their land, had their culture stripped away from them, and sold as property.
And if you're talking about the recent wave of immigrants from Africa, they have maintained their own identity and culture in addition to adopting american customs.
And also just to point out that racial minorities have been mixing in Europe, Africa and Asia for thousands of years. Look at immigration in the Roman era for example.
I'm surprised by pockets of the city I grew up in when I walk a few blocks off the roads I've driven 100s of times. Latin/Somali/Vietnamese/you-name-it neighborhoods I had no idea existed. Sqaure-mile or two neighborhoods within a 1-200sqmi metro, not too surprising.
There's definitely a startling lack of diversity in many of the US' truly rural areas, which is why the current US culture war seems dominantly city versus rural. But there are also fewer truly rural areas than people expect. (The US love of suburban and exurban expansion touched a lot of the country.)
I'm not speaking about regional differences, those exist in pretty much every country.
And it is also important to point out that regional differences are much more stark in India than in the US. Most Americans have only ever met ethnic minorities who have assimilated into being Americans. That would not be considered an ethnic difference in many racial philosophies.
America deserves it's fair share of criticism, but to criticize America as having no/limited experience with diverse cultures shows pretty gross ignorance.
I actually meet a lot of Indians who critise the US over places like Europe and South East Asia because of the lack of mixing between races/ethnicities in the US. I often get Americans in East Asia who don't understand that ethnic minorities from other parts of the world frequently make friends across ethnic boundaries. In America you are divided by race, whereas in the rest of the old world people mix like a port market - people in America seem to forget that inter-race and inter-ethnic immigration has happened across the old world for millennia, and they have been mixing for thousands of years.
It's hard to pin point your opinion because it keeps shifting--are you saying the US has racism? Are you saying people in the US don't mix with other races? Are you saying American's don't have experience with other cultures?
I often attend a lot of events where you get diaspora from across the world, and one thing that all the Indians will agree on is that Indian American don't mix with natives as much as Indians in other parts of the world. This would be a type of racism in most European and Asian racism philosophies.
The other point is that most minorities in the US are highly assimilated into American culture and American norms. And most Americans have had very little experience of anything more drastic than Canada or possibly Hispanics (which is itself a very American concept). Americans drastically tend to underestimate just how different other cultures are and quickly jump to racism - I've been in a lot of situations in third countries where Indian Americans and other Americans call racism on "problems" they have that are considered normal in places like the UK or Australia.
Every ethnic group that has immigrated to America (including Europeans) formed communities with others from their own country of origin.
That isn't an American thing. That exists in every country. As does the disdain for immigrants who forcibly avoid assimilating into local culture. In fact, every major European country I know has seen rise in nationalism fueled entirely by anti-immigrant sentiment.
I find they are disappointed because the wealthy are often the first to travel and live multiple-house nomad lifestyle. Which is nothing like being a nobody who has only average income. An actor traveling all over the world with a personal assistant and businesses arranging everything is who they hear about most as the nomads of the world. As they are the big sports stars, film stars, book authors, musicians - doing their show.
But a lot of musicians and such will tell you that it is by no means easy to live on the road and to follow your own path.
Back in the 1980's, George Lucas and Joseph Campbell really tried to make this knowledge clear to people. Campbell: "They've moved out of the society that would have protected them, and into the dark forest, into the world of fire, of original experience. Original experience has not been interpreted for you, and so you've got to work out your life for yourself. Either you can take it or you can't. You don't have to go far off the interpreted path to find yourself in very difficult situations. The courage to face the trials and to bring a whole new body of possibilities into the field of interpreted experience for other people to experience -- that is the hero's deed."
Most people in 2023 wave around light sabers and have never bothered to study any of the things Lucas filmed about the mythology interpretation and human history of experiences.
“One must travel, to learn. Every day, now, old Scriptural phrases that never possessed any significance for me before, take to themselves a meaning.” ― Mark Twain, The Innocents Abroad