Asked if I’m a Jew

Hi everyone I was just recently in New York City, and I stayed there for about 5 days. It caught my attention that I was asked if I was Jewish 3 different times, I replied to them that I wasn’t but I am curious as of why they were interested to know if I was Jewish. I’m catholic, but I do have Jewish ancestors in my family tree. I’m just curious lol. Thank you guys!