Thanks for responding, everyone. Clearly the situation was more complex than I had imagined. I was assuming the reasons were economic, but clearly there might have been political reasons as well.
Cheechaw--my family didn't settle in New York. They settled in a town called Chicopee outside of Springfield, Massachusetts. There's a very large Polish community there, and I remember going to the Keilbasa festival as a young girl and paying a dollar to see the world's largest keilbasa. LOL. (Sadly, they've done away with that festival.)
Can anyone recommend a good book on Polish history? I picked up some ancient tome from my local library but it was pretty dull and unreadable. (And I have a high tolerance for dry material.)
Oh, one more thing--
I was just told that they came from the Tarnów area of Poland. If I'm correct, that particular area was under Autria-Hungarian rule at the time?
If anyone has any interesting cultural/historical facts about that area, I'd love to hear them.