A new survey shows that mainline Protestants, the religious group that has dominated America’s religious terrain for most of the country’s existence, and Catholics, the largest single denomination in the country, may be beginning to ceding size and influence to new religious groups. The 2012 Religious Congregations and Membership Survey (RCMS), released on May 1, shows that the Church of Jesus Christ of Latter-Day Saints (in other words, Mormonism) reported 2 million new adherents and new congregations in 295 counties where no Mormons lived a decade ago, making Mormonism the fastest-growing religious group in the United States. Muslims came in second, with growth of 1 million adherents in 197 new counties.

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