America remains a largely Christian nation, although less so than in the past. Seventy-four percent of Americans identify with a Christian religion, and 5% identify with a non-Christian religion. The rest of the U.S. adult population, about 21%, either say they don’t have a formal religious identity or don’t give a response.
Religious Identification in the U.S.: 2016
% Protestant/Other Christian 48.9 Catholic 23.0 Mormon 1.8 Jewish 2.1 Muslim 0.8 Other non-Christian religion 2.5 None/Atheist/Agnostic 18.2 No response given 2.6 Based on 173,229 interviews conducted Jan. 2-Dec. 19, 2016 GALLUP The dominance of Christianity in the U.S. is not new, but it has changed over time. The U.S. has seen an increase in those with no formal religious identity (sometimes called “nones”) and a related decrease in those identifying with a Christian religion. Since 2008, when Gallup began tracking religion on its daily survey, the “nones” have increased by six percentage points, while those identifying as Christian have decreased by six points. The 5% who identify with a non-Christian religion has stayed constant.
In the late 1940s and 1950s, when Gallup began regularly measuring religious identity, over nine in 10 American adults identified as Christian — either Protestant or Catholic — with most of the rest saying they were Jewish.
Via Gallup