A side note on religion stats.. Mentioned long ago, but still one of the more amazing maps I have ever seen is this interactive map of the US with data on the predominant religious denomination by county. Check out:
I never realized this. But just by eyeballing that map, it looks like Elk County is the most Catholic county in the US outside of some border counties in the Southwest.
But on Pittsburgh's Jewish population. I once scanned this document from the 1910 census which showed that at the time the 2nd largest foreign born groups in the City of Pittsburgh were those listed as Russian. More than Irish or Italian by far which surprises me. I presume that captures various groups of Jewish immigrants around the turn of the previous century and Russia at the time would have included more countries that we currently define as Russia today as well.