A new survey shows that the US is growing less religious; USA Today maps it.
It's an interactive map that lets you plot the percentages of the states' populations that are Catholic, other Christian, other religions, or belong to no religion for both 1990 and 2008. This image shows the non-religious populations as of 2008.
They're a much larger percentage of the population than they were even one generation ago: 15%, compared to 8% in 1990. That makes them a larger bloc than every other group except Catholics and Baptists. In 1990, fewer than 10% of the population was non-religious in 36 states, not counting Alaska and Hawaii (the least important states, according to this and many other maps); by 2008, that was the case in just 6 states. Oregon was the least religious state in 1990, with 18% claiming no religion; there are now a dozen states above 20%. These numbers are pretty remarkable.
The geographic distribution of non-religion is pretty unsurprising. States in New England and the West are the least religious; states in the South and the Plains are the most religious. The least religious state in the country is now Vermont, where a full 34% of people claim no religion, up from 13% in 1990. At the other end of the spectrum, just 5% of Mississippians claim no religion. Overall, the percentage of the population that calls itself Christian has shrunk by 11%