Just this week I was showing students here at the seminary the maps of the 2000 census. I was hoping to have updated materials. Now they're out.
The 2010 U.S. Religion Census: Religious Congregations & Membership Study (RCMS) is a county-by-county examination of the various religious traditions and confessions of the United States. It is utterly fascinating stuff. WARNING: If you're a map nerd like I am, this may gobble up a good portion of your day.