J. Gordon Melton, professor of American religious history, explained that although Mainline denominations have lost membership in recent years, the number of denominations in America has increased steadily since the 1960s. Now, there are over 1,000 denominations in the U.S. | J. Gordon Melton, professor of American religious history, explained that although Mainline denominations have lost membership in recent years, the number of denominations in America has increased steadily since the 1960s. Now, there are over 1,000 denominations in the U.S. |