hmm.. a similar question came in a few days ago, but I can't find it now -has it been deleted? If any of the commenters in that thread still have a link, could you pass it along - it had some good information. Meanwhile, here's a discussion from last year to get you started

• Was Christopher Columbus a Jew?

edit: Google search comes through: here's last week's deleted post

• What is the evidence that Columbus was in fact Jewish?