Modern scholars who study contemporary American Protestantism commonly divide the movement into two main groups. Mainline Protestantism is a broadly inclusive group of theologically liberal denominations such as the Episcopal Church, the Evangelical Lutheran Church in America, the United Church of Christ, and the Presbyterian Church (USA). “Sideline” Protestants are members of smaller, breakaway denominations or independent churches that are “Bible believing.” This division is roughly a century old, and it reflects the outcome of what is commonly called the Fundamentalist-Modernist Controversy (modernism, in this context, is the equivalent of theological liberalism). The conflict began in the Northern Presbyterian church, officially known at the time as the Presbyterian Church in the United States of America (PCUSA); it was separated from Southern Presbyterians from 1861 to 1983. However, the controversy would ultimately disrupt every Protestant denomination in North America. As we survey this controversy, we will see that a proper assessment of the conflict suggests that the name of the controversy is misleading.