There are still people speaking a century old dialect of Italian that nobody speaks in Italy any more on Statin Island in New York and they do have Italian newspapers and so on. Yes, my father knew immigrant families where the kids would get hit for not speaking English at home because the parents wanted them to learn English but there were also ethnic enclaves that still exist. The kids can’t help but being exposed to English if they look at the other four hundred channels on their cable box.
My mother is an Italian immigrant who only speaks Italian to her children and her grand children primarily so that they can have meaningful relationships with their Italian cousins. So, I know at least a little of what I speak.
And yes, there are still pockets, very very small pockets of population in the States that speak Italian as a primary language, maybe even sole language. But, the scale today or even in 1920 pales in comparison to what's going on in America's Latino barrios. Nor was Italian, or any other non-English language for that matter, spoken with such ubiquity across the country.
You say that children can't help but learn English, but that's clearly not the case in today's reality. Second generation Latino children are years behind their non-Latino counterparts because the bulk of their primary education is spent learning English as it's not spoken at home or in the neighborhood - it's a deficit from which they never recover and is one of, if not the reason that Latino children have such high drop out rates relative to the general population.
The failure of immigrant populations to assimilate is not a uniquely American phenomenon. It can be seen in other countries and the results are almost always the same - friction, isolation, frustration and resentment - which all lead to significant social problems for both the immigrants and their hosts.