In poll backed by information from over 150,000 interviews, a Gallup study showed that more than half of the Americans interviewed practice a Christian religion.
The study involved interview responses taken in 2014 and has revealed certain key points. One conclusion from the study is that America is still a predominantly Christian country. Also, Americans as a general rule are observant people, with 8 in 10 respondents saying they attend religious services.
Mormons attend religious services most often while Jews and other non-Christians attend the least, based on the survey results.
Of the respondents who were probed regarding their religious preference and answered "Christian", 50% specified they were Protestants or another non-Catholic denomination. About a quarter of them were Catholics.
Based on the study, less Christians now identify themselves as Protestants, especially when compared to decades ago. Back in the 1950s, Gallup poll revealed that over half of the Americans surveyed called themselves Protestants. Today, over 90% of Americans who say they are religious call themselves "Christian".
The poll doesn't mean to say that the Protestant denomination isn't a majority anymore. Protestants still are the biggest group in all of the religious classes in America.