
A 1978 study by Charles Heatwole identified the Bible Belt as the region dominated by 24 fundamentalist Protestant denominations, corresponding to essentially the same area mapped by Zelinsky. On the other hand, areas in the South which are not considered part of the Bible Belt include heavily Catholic Southern Louisiana, central and southern Florida, which have been settled mainly by immigrants and Americans from elsewhere in the country, and overwhelmingly Hispanic South Texas. In addition, the Bible Belt covers most of Missouri and Kentucky and southern parts of Illinois, Indiana, and Ohio. The region thus defined included most of the Southern United States, including most of Texas and Oklahoma, and in the states south of the Ohio River, and extending east to include central West Virginia and Virginia, from the Shenandoah Valley southward into Southside Virginia and North Carolina. In a 1961 study, Wilbur Zelinsky delineated the region as the area in which Protestant denominations, especially Southern Baptist, Methodist, and evangelical, are the predominant religious affiliations. The name "Bible Belt" has been applied historically to the South and parts of the Midwest, but is more commonly identified with the South. The term is now also used in other countries for regions with higher religious doctrine adoption. Mencken, who in 1924 wrote in the Chicago Daily Tribune: "The old game, I suspect, is beginning to play out in the Bible Belt." In 1927, Mencken claimed the term as his invention. The earliest known usage of the term "Bible Belt" was by American journalist and social commentator H.

The evangelical influence is strongest in northern Georgia, Tennessee, Alabama, Mississippi, North Carolina, southern and western Virginia, West Virginia, the Upstate region of South Carolina, and East Texas. Whereas the states with the highest percentage of residents identifying as non-religious are in the West and New England regions of the United States (with Vermont at 37%, ranking the highest), in the Bible Belt state of Alabama it is just 12%, and Tennessee has the highest proportion of evangelical Protestants, at 52%. The region contrasts with the religiously diverse Midwest and Great Lakes, and the Mormon corridor in Utah and southern Idaho. Church attendance across the denominations is generally higher than the nation's average. The Bible Belt is a region of the Southern United States in which socially conservative Protestant Christianity plays a strong role in society.
