The mainline Protestant churches (also called mainstream Protestant and sometimes oldline Protestant) are a group of Protestant denominations in the United States that contrast in history and practice with evangelical, fundamentalist, and charismatic Protestant denominations. Some make a distinction between "mainline" and "oldline", with the former referring only to denominational ties and the latter referring to church lineage, prestige and influence. However, this distinction has largely been lost to history and the terms are now nearly synonymous. These terms are also increasingly used in other countries for the same purpose (to distinguish).
Mainline Protestants were a majority of all Christians in the United States until the mid-20th century, but they now constitute a minority among Protestants. Mainline churches include the so-called Seven Sisters of American Protestantism—the United Methodist Church, the Evangelical Lutheran Church in America (not to be confused with Confessional Lutheranism), the Presbyterian Church (USA), the Episcopal Church, the American Baptist Churches, the United Church of Christ, and the Disciples of Christ—as well as the Quakers, Reformed Church in America, African Methodist Episcopal Church (AME) and other churches. The term 'mainline' has also been applied to Canadian Protestant churches that share common origins with their US counterparts. In Mexico, the Anglican Church is historically tied to and formed from the US Episcopal Church. The term is also occasionally used to refer to historic Protestant churches in Europe, Latin America, and South Africa.