my name is Karolina Wentland and I live in Poland.
My great grandparents lived in Wielkopolska which is a region of Poland around Posen. I don't know much about their history and there is not too many people who are still alive and remember details but I heard once a story about my great grandmother's sister who went to USA at the end of XIX century and she became a noun. Have you heard about Sister Wentland who was born in Poland/East Prussia - as you probably know Poland was at that time under German, Austrian and Russian occupation so you may see in Census records names like East Prussia, Russ-Poland or other variants.
If you need any help with research in Poland just let me know. A lot of documents was burnt during World Wars but I believe that still we can find something interesting.