Most of the slave owners in America would have been Protestant, not Jewish. Again, the boats weren't necessarily owned by slave owners, just slave traders. And who were slave traders? Lots of people, including Africans, Dutch, French, and Portuguese.

I do remember that a very small percentage of Americans actually had slaves but I have not double checked that either :P

Slavery is basically a bourgeois activity. Only the very rich could really afford it unless you had a weird situation where you just had one slave that was a domestic servant.