NYC has always been a city where newcomers stay two generations then move out to quieter corners. Neighborhoods that were German or Irish or Jewish or Italian or Scandinavian fifty years ago now show only scattered remnants of those groups as their kids and grandkids all left. Now the newer groups (Indians, Asians, Dominicans) are moving out too, making room for the new newcomers.
It's an old story.
Just how many of these "older" immigrants were illegal, how many went right on welfare and how many wanted nothing to do with becoming American?