By Kent E. Fillinger The number of unaffiliated, nondenominational Christian churches in the United States grew by almost 5,000 congregations and nearly 9 million people from 2010 to 2020, thus making it America’s largest Protestant “denomination,” according to the U.S. Religion Census. In 2010, unaffiliated, nondenominational Christian churches had an estimated 12,241,329 adherents in 35,496 congregations, which represented 4 percent of the overall population. By 2020, the number of people worshipping in those churches grew to 21,095,641, and their share of America’s religious population increased to 13.1 percent, representing 6.4 percent of the nation’s population. How Many Churches Do We