I'm sorry if this seems like "Let's Pick on IdleBoast Day," but speaking as someone who has lived her entire life in the U.S. and who has more than average knowledge about the U.S., I couldn't disagree with you more.
I think I expressed myself badly; I did not mean that the
segregation enclaves were forced - they grew because the immigrants chose to live close together. If I recall correctly, the core of such an area would [sometimes] be the passengers of a single ship, but they stayed together because they were not as accepted by the local population [of previous immigrants] as Lady Liberty's plaque would have us believe, and once they were in a recognisable area the lack of integration became self-perpetuating.
We do have immigrant areas in the UK, but they tend not to last - the Jewish quarters, Chinatowns etc still have an above-average representation of the eponymous minority, but the edges blur, the population is "diluted" by "locals" moving back in, gentrification, or new waves of immigrants from other parts of the world, until many of them are little more than areas marked on maps in tourist guide books. As I said elsewhere, the UK & Europe have been "dealing" with immigrants [often arriving as armies of occupation] for centuries, far longer than the US has even had a name.
The "problem" is, quite frankly, blown massively out of proportion by the kind of people who use "alternative facts", and often for similar reasons to past dictators; it is always easier to control those within if they are afraid of those beyond.