In Britain and most of Europe, some form of U-speak exists: old-money language has certain features that distinguish it from other language. In Dutch, it doesn't really have a name, but it is still very much alive. I believe the same applies to England. The phenomenon is just very hard to research; that is why not much information about it is available on the internet, except about England, partly because of several famous studies on the subject (see Wikipedia). But even there the few reliable sources are several decades old, while U-speak changes continuously.
Do Americans have their version of U-English? How does it differ from British U—or is it very much alike? What are some examples? It might be that the term is just not applicable to American society for some reason (though I doubt that).
It would be best to have some references, like scientific articles or interviews or corpus finds, if such are available.
Edited: Emily Post wrote extensively about what resembles European U-speak to a high degree, in many cases even literally:
People who say “I come,” and “I seen it,” and “I done it” prove by their lack of grammar that they had little education in their youth. Unfortunate, very; but they may at the same time be brilliant, exceptional characters, loved by everyone who knows them, because they are what they seem and nothing else. But the caricature “lady” with the comic picture “society manner” who says “Pardon me” and talks of “retiring,” and “residing,” and “desiring,” and “being acquainted with,” and “attending” this and that with “her escort,” and curls her little finger over the handle of her teacup, and prates of “culture,” does not belong to Best Society, and never will! — Emily Post, Etiquette (1922).
Since America has old money too, and a form of U-English existed there in the 1920s that much resembled British U-speak, it would seem highly unlikely for America not to have its modern variant(s). The problem is that it can only be observed by those who know what to look for, because it is an otherwise very inconspicuous phenomenon.