The religion 

PRINCETON, NJ -- The large majority of Americans -- 77% of the adult population -- identify with a Christian religion, including 52% who are Protestants or some other non-Catholic Christian religion, 23% who are Catholic, and 2% who affiliate with the Church of Jesus Christ of Latter-day Saints. Another 18% of Americans do not have an explicit religious identity and 5% identify with a non-Christian religion.

This breakdown is essentially the same as it was in 2011. Compared with last year, Protestant and Catholic identification dropped.

The 2012 findings on the breakdown of religious identification in the American population are based on more than 326,000 Gallup Daily tracking interviews conducted between Jan. 2 and Nov. 30. (Frank Newport)

Reference from www.gallup.com/poll/159548/identify-christian.aspx