Bedrockgames
I post in the voice of Christopher Walken
If the person from Newton is Jewish, then "my people are from Krakow" probably involves a story with tragic aspects. I speculate that your friends knew, and trusted, that you'd handle that with compassion and respect.
Where I grew up it was mainly Jewish, Italian and Irish. So it was one of the first things that tended to come up. It was never done disrespectfully, but it wasn't particularly touchy feely either. In Boston people are generally pretty rough with each other, but in a way that is meant to be friendly busting of chops. I think that kind of cultural detail is one that gets lost in these debates (and one I think Dannyalcatraz was pointing to when he mentioned that 'where are you from' is more common where he comes from.
Anyone who actually had ties to the holocaust, that was generally taken pretty seriously (in fact my high school had a lot of courses that we took (or at least segments of courses) on the holocaust. And I even met survivors working at a local Jewish bakery (but one of the first things I was asked by them is if I was Jewish or Italian). Those kinds of meetings were not something taken lightly.
I also believe Hussar about people asking "Where are you from?" and then *insisting* on drilling down to ancestry. The insistence is rude.
Of course it is. My first comment on this topic was to explain why I thought it was particularly insulting for Asian people (because they get asked where they are from when other groups don't). I was just adding a note in there about people asking about ethnic backgrounds in the north east (because my experience out west was people thought more in terms of race there than ethnic groups).