The Methodist Church's rise and recent decline is perhaps the most statistically striking story in American religious history. At the time of the American Revolution, the denomination was tiny. English Methodist founder John Wesley was hostile toward American independence, which badly hampered the church's growth in America. After the Revolution, the American church began to operate independently from English Methodists. The legendary Methodist "circuit riders" began reaching the American backcountry, riding on horseback to reach every nook and cranny of the Appalachian frontier and Mississippi River Valley. In 1770, there were about 20 Methodist churches in America. By 1860 that number had grown to more than 19,000.

Methodist growth in America continued into the...