A correspondent has proposed an interesting question:
I am trying to find out about communities in the US/Canada that have historically been non-English speaking and are still hanging on to their native tongue (no matter how tenuous that grip may be). For languages like French, German, or Sorbian, this is easy enough using Ethnologue or the Census data—because immigration from those language groups dried up many years ago, any community that still speaks one of them must be “historic”. However, for tongues like Russian, Spanish, Chinese, or Japanese, it’s impossible to distinguish which are the areas of historical usage, and which are just full of recent immigrants. Do you know any resources on the internet that could help me out?
Just by way of clarification:
1.) For the purposes of this research, I am not interested in languages that are native to North America.
2.) By historic, I mean any place that a.) has been speaking that language since at least the 19th century, and b.) where the language maintenance is the result of it being handed down in that community, rather than a result of continual immigration of people of that tongue. For example, even though San Francisco would be considered a historically Chinese-speaking city, I am not interested in it because it continues to attract Chinese-speaking immigrants. However, I would be interested in a place where Chinese people came in the 19th century, the immigration from China dried up, but the language has been maintained.
So: any suggestions?