"That is NOT how most immigrants arrived 100 years ago....and 100 years ago, not being fluent in English was not the issue it is now."
Maybe thats because you didn't need to learn English on the farm but if you look closely you will see that many farming communities were mostly Danish or mostly German or what have you. Same for the cities. Cities were often mostly Italian or mostly Scandanavian or mostly English or... Even within the cities you had districts of people who shared a common language. Its human nature to want to be with your own kind.
So whats so different about people from Mexico or Korea wanting to form communities or shopping areas where they can converse in the language of home and buy specialty items from the old country as long as they abide by the laws of their new country?
I think the solution is to give amnesty to those who are already here and tighten the immigration policies at the same time. You will need their contributions to Social Security for your old age. Immigration quotas can be set and immigrants can be screened for job skills that are needed.
The endless caravans of day labourers coming across the border are more of a problem than those who actually live and work here.