The United States is on the verge of becoming a minority Protestant country; the number of Americans who report that they are members of Protestant denominations now stands at 51%. Moreover, the Protestant population is characterized by significant internal diversity and fragmentation, encompassing hundreds of different denominations loosely grouped around three fairly distinct religious traditions — evangelical Protestant churches (26.3% of the overall adult population), mainline Protestant churches (18.1%) and historically black Protestant churches (6.9%). While Americans who are unaffiliated with any particular religion have seen the greatest growth in numbers as a result of changes in affiliation, Catholicism has experienced the greatest net losses as a result of affiliation changes. While nearly one-in-three Americans (31%) were raised in the Catholic faith, today fewer than one-in-four (24%) describe themselves as Catholic. These losses would have been even more pronounced were it not for the offsetting impact of immigration. The 2008 U.S. Religious Landscape Survey finds that among the foreign-born adult population, Catholics outnumber Protestants by nearly a two-to-one margin (46% Catholic vs. 24% Protestant); among native-born Americans, on the other hand, Protestants outnumber Catholics by an even larger margin (55% Protestant vs. 21% Catholic). Read More

Russell Heimlich  is a former web developer at Pew Research Center.