The geographic pattern is striking.
"Catholics are most visible in much of the Northeast and Canada, with Lutherans taking the Midwest, Baptists the Southeast, and Mormons unsurprisingly taking much of the mountain states. Methodists, interestingly, seem to primarily be most visible in a thin red line between the Southern Baptists and everyone else."
Now check out their map of Christianity in Europe, where they note the "fascinating split between Orthodox Eastern Europe, Protestant Germany, and Catholic everywhere else."
And, bringing it all together, here's their map of Christians around the world.
This article available online at:
http://www.theatlantic.com/international/archive/2010/03/the-christianity-map/37619/