Two divisions of American Protestant churches or denominations appear under many names or attributes, but Evangelical and Mainline are the most prominent of these names.
Evangelical Churches = more recent churches with newly converted members; emphases on decline of secular society, end-times, individual salvation, afterlife, devotion to family plus high reproduction rates; patriarchal leadership; pro-life and uncomfortable with LGBT. Class status: working class to middle class (though certainly wealth rises from these churches). Emotional appeals and behaviors. Distinctions b/w Evangelical and Fundamentalist churches are sometimes based on the degree of absorption into everyday secular society, with Evangelicals peacefully co-existing and Fundamentalists seeking separation or isolation from worldliness, but traditions like home-schooling and phrases like "We are in the world but not of the world" show much overlap between these terms.
Examples: Southern Baptists, Church of Christ, Assembly of God, early Methodists; many non-denominational or unaffiliated churches; Mormons, Seventh-Day Adventists, Jehovah's Witnesses are Evangelical in many regards but may be considered outsiders.
Mainline Churches (possibly named for early 20c "Main Line" Railroad through affluent Philadelphia suburbs) have supplied many of the nation's historic leaders in politics, business, academics, so that these churches are sometimes associated with older, more settled families who have some comfort with the world and don't so strongly reject the world for the afterlife or emphasis on the unborn. Correspondingly, these churches stress social justice over individual salvation. Mainline churches may devote more funds to social programs than to expanding their churches. They tend to support equality for women, gays, and the poor. Consequently their membership is "open and inclusive" to those who feel less welcome in Evangelical churches. However, Evangelical churches continue to grow through high reproduction rates, conversion, and development of churches into community centers with gymnasiums and theaters, while Mainline membership has fallen rapidly since the 1960s owing to low reproduction rates, less enthusiasm for conversion and mission work, and the tendency of children to drift out of churches altogether, partly from increasing association of Christianity with right-wing politics.
Examples: Episcopalians, most Presbyterians, most Lutherans, Congregationalist / United Church of Christ, most Methodists, Disciples of Christ, Northern Baptists. Quakers and Moravians may also be considered Mainline. Most Mainline churches are located in the Northeastern and Midwestern United States.
National Council of Churches