The Mainline Protestant churches (which are also sometimes called "mainstream American Protestant" and "oldline Protestant") are a group of Protestant churches in the United States that contrast in history and practice with evangelical, fundamentalist, and charismatic Protestant groups. Mainline Protestants were a majority of all churchgoers in the United States until the early 20th century, but now constitute a minority among Protestants. Mainline churches include the United Methodist Church (UMC), the Evangelical Lutheran Church in America (ELCA), the Presbyterian Church (U.S.A.) (PCUSA), the Episcopal Church, the American Baptist Churches, the United Church of Christ (Congregationalist), the Disciples of Christ, and the Reformed Church in America, among others.
Mainline churches share a common approach to social issues that often leads to collaboration in organizations such as the National Council of Churches. Because of their involvement with the ecumenical movement, mainline churches are sometimes (especially outside the United States) given the alternative label of ecumenical Protestantism. These churches played a leading role in the Social Gospel movement and were active in social causes such as civil rights and equality for women. As a group, the mainline churches have maintained religious doctrine that stresses social justice and personal salvation. Politically and theologically, contemporary mainline Protestants tend to be more liberal than non-mainline Protestants.
Members of mainline denominations have played leadership roles in many aspects of American life, including politics, business, science, the arts, and education. They founded most of the country's leading institutes of higher education. Since the 1960s, however, mainline groups have shrunk as a percentage of the American population as increasing numbers of American Protestants have come to affiliate instead with fundamentalist, evangelical, or charismatic churches, or with no church at all. Mainline denominations peaked in membership in the 1950s and have declined steadily in the last half century. From 1965 to 1988, mainline church membership declined from 31 million to 25 million, then fell to 21 million in 2005. While in 1970 the mainline churches claimed most Protestants and more than 30 percent of the population as members, today they are a minority among American Protestants, claiming approximately 15 percent of American adults among their adherents in 2009.
Origin and usage of the term 
The term "mainstream Christian" in academic usage is not equivalent to "mainline Protestant" and is often used as an attempt to find non-loaded sociological vocabulary in distinguishing "orthodoxy" and "heresy." Hence in christological and doctrinal reference "mainstream Christianity" is often equivalent to "Trinitarianism." In Britain and Australia the term "mainline Protestant" is not used, and "mainstream" does not mean "liberal" Protestant.
The term "Mainline Protestant" was coined during debates between modernists and fundamentalists in the 1920s. Several sources claim that the term is derived from the Philadelphia Main Line, a group of affluent inner suburbs of Philadelphia that were settled along the Pennsylvania Railroad Main Line, and that most residents of these suburbs belonged to mainline denominations, though this may be a folk etymology. Today, most mainline Protestants remain rooted in the Northeastern and Midwestern United States. Charles H. Lippy (2006) defines the term as follows: "the term "mainline Protestant" is used along with "mainstream Protestant" and "oldline Protestant" to categorize denominations that are affiliated with the National Council of Churches and have deep historic roots in and long-standing influence on American society."
Some have criticized the term "mainline" for its alleged ethnocentric and elitist assumptions, since it almost exclusively described white, non-fundamentalist Protestant Americans from its origin to the late twentieth century.
- With almost 8 million U.S. members in 2008 (down from over 11 million in 1968), the United Methodist Church remains the largest U.S. mainline Protestant denomination.
- The second largest mainline denomination is the Evangelical Lutheran Church in America (ELCA), with approximately 4.5 million members in 2009 (down from 4.7 million members in 2008).
- The third largest mainline denomination is the Presbyterian Church (U.S.A.), with approximately 1.95 million members in 2011 (down from 2.4 million members in 2006).
- Fourth in size is the Episcopal Church, with approximately 1.95 million members in 2010 (down from 2.1 million members in 2008).
- American Baptist Churches USA are fifth in size, with approximately 1.3 million members (2008).
- The United Church of Christ has 1.1 million members (2008).
- The Christian Church (Disciples of Christ) claimed 691,160 in 2008.
- Religious Society of Friends (Quakers) 350,000 members
- Reformed Church in America 254,485 members (2008)
- International Council of Community Churches 73,174 members (2006)
- National Association of Congregational Christian Churches 65,392 members (2002)
- North American Baptist Conference 64,565 members (2002)
- Universal Fellowship of Metropolitan Community Churches 15,666 members (2006)
- Moravian Church in America, Northern Province 20,983 members (2008)
- Moravian Church in America, Southern Province 21,513 members (1991)
- Latvian Evangelical Lutheran Church in America 12,000 members (2007)
- Estonian Evangelical Lutheran Church
- Congregational Christian Churches, (not part of any national CCC body)
- Moravian Church in America, Alaska Province
The Association of Religion Data Archives has difficulties collecting data on traditionally African American denominations. Those churches most likely to be identified as mainline include these Methodist groups:
- African Methodist Episcopal Church
- African Methodist Episcopal Zion Church
- Christian Methodist Episcopal Church
Some denominations with similar names and historical ties to mainline groups are not considered mainline. The Southern Baptist Convention, Lutheran Church – Missouri Synod, the Churches of Christ, the Presbyterian Church in America (PCA), and the Anglican Church in North America (ACNA) are often considered too conservative for this category and thus grouped as evangelical.
Mainline churches hold a wide range of theologies—conservative, moderate and liberal. The inclusion of a denomination in the mainline Protestant category does not imply that every member of that denomination, nor even every member of their clergy, accepts some of the beliefs generally held in common by other mainline churches. They allow considerable theological latitude. Moreover, mainline denominations have within them Confessing Movements or charismatic renewal movements which are more conservative in tone.
About half of mainline Protestants describe themselves as liberal. Liberal theology emerged from the anti-slavery debates in the antebellum United States, a turning point in American theology. The issue of slavery forced antislavery theologians, including William Ellery Channing, Francis Wayland, and Horace Bushnell, to reconcile what they perceived as contradictory loyalties to the Bible and to antislavery reform. Unable to use the letter of the Bible to make a scriptural case against slavery in itself, the moderates argued that although slavery had been acceptable in biblical times, it had become a sin. Antislavery Protestantism required a theory of moral progress, an idea that became fundamental to the development of late-19th-century liberal Evangelical Protestantism. The antislavery argument from moral progress, along with the moral progress represented by abolition, established a progressive conception of revelation that was further developed by late-19th-century liberal theologians, including Newman Smyth, Lyman Abbott, and Theodore Munger. Once they had adopted the idea that moral values evolve, it was not hard to come to terms with the impact of modernity, critical biblical scholarship, and Darwinism.
Mainline Christian groups are often more accepting of other beliefs and faiths. These church bodies are often comparatively more comfortable with gender inclusive language in contemporary translations of the Bible. Mainline churches tend to be open to new ideas, new understandings of morality, and societal changes without abandoning what they consider to be the historical foundations of the Christian faith. For example, mainline churches are open to the ordination of women and have become increasingly open to gay ordination.
Nearly one-third of mainline Protestants call themselves conservative, and most local mainline congregations have a strong, active conservative element. Mainline denominations are historically Trinitarian and proclaim Jesus Christ as Lord and Son of God; they adhere to the historic creeds such as the Nicene Creed, the Apostles' Creed, and the Athanasian Creed.
In practice, mainline churches tend to be theologically moderate and influenced by higher criticism, an approach used by scholars to separate the Bible's earliest historical elements from perceived later additions and intentional distortions. Mainline denominations generally teach that the Bible is God's Word in function, but that it must be interpreted both through the lens of the cultures in which it was originally written, and examined using God-given reason. A 2008 survey conducted by the Pew Research Center found that only 22 percent of the 7,500 mainline Christians surveyed said the Bible is God's Word and is to be interpreted as literally true, word for word. Thirty-eight percent thought that the Bible is God's Word but is not to be taken literally, word for word. Twenty-eight percent said the Bible was not the Word of God but was of human origin.
Social justice 
The mainline denominations emphasize the biblical concept of justice, stressing the need for Christians to work for social justice, which usually involve politically liberal approaches to social and economic problems. Early in the 20th century, they actively supported the Social Gospel.
Mainline churches were basically pacifistic before 1940, but under the influence of people such as Reinhold Niebuhr they supported World War II and the Cold War. They have been far from uniform in their reaction to homosexual behavior, though generally more accepting than the Catholic Church or the more conservative Protestant churches.
Protestant churches as a whole have held steady in total membership in the last half century, but since the national population has grown they have shrunk from 63% of the population in 1970 to 54% by 2000. The Mainline denominations comprised 55% of all Protestants in 1973, and 46% in 1998.
While the term "mainline" once implied a certain numerical majority or dominant presence in mainstream society, that is no longer the case. Both evangelical and fundamentalist Christian groups have been growing, but mainline Christianity—both membership and worship attendance—has been shrinking.
The number of mainline congregations in the U. S. declined from more than 80,000 churches in the 1950s to about 72,000 in 2008. About 40% of Mainline Protestants in the 1990s were active in church affairs, compared to 46% of the conservatives.
Various causes have been cited, including monotonous and ponderous liturgies, intimidating worship surroundings, and too much tradition. Behaviorally, only one-third (31 percent) of mainline adults believe they have a personal responsibility to discuss their faith with people who have different beliefs. Tenure of pastors in mainline churches tends to be somewhat brief. On average, these pastors last four years before moving to another congregation. That is about half the average among Protestant pastors in non-mainline churches.
Demographers have examined the statistical basis of the long-term decline in the mainstream membership versus the growth in the conservative denominations.
There are four basic factors: birth rates; switching between denominations; departure from Protestantism; and conversions from non-Protestant sources. By far the main cause is birth rates—low for the mainline bodies, and high for the conservatives. The second most important factor is that fewer conservatives switch to mainline denominations than before. Secularization (moving to "no religion") is a third factor.
Despite speculation to the contrary, switching from a mainline to a conservative denomination is not important in accounting for the trend, because it is fairly constant over the decades. Finally, conservative denominations have had a greater inflow of converts.
Evidence from the General Social Survey indicates that higher fertility and earlier childbearing among women from conservative denominations explains 76% of the observed trend: conservative denominations have grown their own. Mainline denomination members have the lowest birthrate among American Christian groups. Unless there is a surge of new members, rising death rates are predicted to diminish their ranks even further in the years ahead.
Statistical analysis gives no support for the notion that theological or social conservatism or liberalism has much impact on long-term growth trends.
Mainline churches have had difficulty attracting minorities, particularly Hispanics. Hispanics comprise 6 percent of the mainline population but 16 percent of the US population. The Barna Group considers the failure of mainline Protestants to add substantial numbers of Hispanics to be portent for the future, given both the rapid increase of the Hispanic population as well as the outflow of Hispanics from Catholicism to Protestant churches in the past decade, most of whom are selecting evangelical or Pentecostal Protestant churches.
Some other findings of the Barna Group:
- From 1958 to 2008, mainline church membership dropped by more than one-quarter to roughly 20 million people—15 percent of all American adults.
- From 1998 to 2008, there was a 22 percent drop in the percentage of adults attending mainline congregations who have children under the age of 18 living in their home.
- In 2009, nearly 40 percent of mainline church attendees were single. This increase has been driven higher by a rise in the number of divorced and widowed adherents.
- From 1998 to 2008, volunteerism dropped 21 percent; adult Sunday school participation decreased 17 percent.
- The average age of a mainline pastor in 1998 was 48 and increased to 55 by 2009.
- Pastors on average remain with a congregation for four years compared to twice that length for non-mainline church leaders.
Recent statistics from the Pew Forum provide additional explanations for the decline.
- Evangelical church members are younger than those in mainline denominations. Fourteen percent of evangelical congregations are between 18 and 29 (compared to 2 percent), 36 percent between 30 and 49, 28 percent between 50 and 64, and 23 percent 65 or older.
Not paralleling the decline in membership is the household income of members of mainline denominations. Overall, it is higher than that of evangelicals:
- 25% Reported less than a $30,000 income per year.
- 21% Reported $30,000-$49,999 per year.
- 18% Reported $50,000-$74,999 per year.
- 15% Reported $75,000-$99,999 per year.
- 21% Reported an income of $100,000 per year or more, compared to only 13 percent of evangelicals.
Protestantism's hundreds of different denominations are loosely grouped according to three fairly distinct religious traditions—evangelical Protestant churches (26.3 percent of the overall adult population), mainline Protestant churches (18.1 percent) and historically black Protestant churches (6.9 percent).
The Association of Religion Data Archives ARDA counts 26,344,933 members of mainline churches versus 39,930,869 members of evangelical Protestant churches.
- Moorhead, James H. World Without End: Mainstream American Protestant Visions of the Last Things, 1880–1925. (Religion in North America, number 28.) Bloomington: Indiana University Press. 1999. Pp. xxii, 241
- Charles H. Lippy Faith in America: Organized religion today 2006 THE MAINLINE PRIOR TO THE ERA OF DECLINE
- David A. Roozen (2004). "Oldline Protestantism: Pockets of Vitality Within a Continuing Stream of Decline". Hartford Institute for Religion Research Working Paper 1104.1, Hartford Seminary. Retrieved 01/09/2012.
- William McKinney (March 12, 2010). "Revisioning the Future of Oldline Protestantism". The Christian Century. pp. 1014–1016. Retrieved 01/09/2012.
- Audrey Barrick (November 8, 1989). "Survey Tracks Trends in Evangelical, Oldline Congregations". Christian Post. Retrieved 01/09/2012.
- Robert Wuthnow and John H. Evans, eds. The Quiet Hand of God: Faith-Based Activism and the Public Role of Mainline Protestantism (2002) p 4
- Richard G. Hutcheson, Jr., Mainline Churches and the Evangelicals: A Challenging Crisis? (Atlanta, Georgia: John Knox Press, 1981), p. 36-37.
- Oliver, Thomas. "Where have all the Protestants gone?" USA Today. 1 March 2010, p.17A
- Chang, Perry. "Recent Changes in Membership and Attendance. " Presbyterian Church (U. S. A.) Nov. 2006. Web: Presbyterian Church (U. S. A.)
- McKinney, William. "Mainline Protestantism 2000." Annals of the American Academy of Political and Social Science, Vol. 558, Americans and Religions in the Twenty-First Century (Jul., 1998), pp. 57-66.
- Mark A. Noll, A History of Christianity in the United States and Canada (1992) p 465
- Ellen W. Linder, ed. Yearbook of American & Canadian Churches: 2009 (2009)
- Hout, Michael; Greeley, Andrew; Wilde, Melissa J. (2001). "The Demographic Imperative in Religious Change in the United States". American Journal of Sociology 107 (2): 468–500. doi:10.1086/324189.
- Report Examines the State of Mainline Protestant Churches The Barna Group. December 7, 2009. Web: 12 Dec. 2009
- Ismo Dunderberg Beyond gnosticism: myth, lifestyle, and society 2008 "with theological meaning, such as replacing "orthodoxy" with "mainstream Christianity" and "heresy" with terms like "sect,"24 "splinter group," or something similar. These designations may create the impression of greater neutrality and ..."
- Andrew D. Walsh Religion, economics, and public policy 2000 "The term "Mainline Protestant" was coined during the modernist/ fundamentalist debates of the 1920s."
- Lindsay, D. Michael. "Faith in the Halls of Power"
- Martin E. Marty A Nation of Behavers 1980 "the term "Mainline" may be as unfortunate as the pejorative-sounding WASP, but it is no more likely to fall into disuse and may as well be ... Mainline religion had meant simply white Protestant until well into the twentieth century."
- The Mainstream Protestant "decline": the Presbyterian pattern Milton J. Coalter, John M. Mulder, Louis Weeks - 1990 Some would say the term "mainstream" or "mainline" is itself suspect and embodies ethnocentric and elitist assumptions. ... be dropped in favor of talking about "liberal" Protestantism, but such a change presents additional problems"
- Protestant Establishment I (Craigville Conference)
- Hutchison, William, Between the Times: The Travail of the Protestant Establishment in America, 1900-1960 (1989), Cambridge U. Press, ISBN 0-521-40601-3
- NCC - 2009 Yearbook of American & Canadian Churches
- Summary of Congregational Statistics as of 12/31/09, ELCA.
- Summaries of Statistics - Comparative Summaries.
- National Council of Churches News Service. "Trends continue in church membership growth or decline, reports 2011 Yearbook of American & Canadian Churches". February 14, 2011. Retrieved December 29, 2011.
- "American Baptist Churches in the U.S.A.". The Association of Religion Data Archives. Archived from the original on 5 June 2011. Retrieved 2011-05-27.
- Mainline protestant denominations
- Reformed membership
- ICCC membership
- NACCC membership
- UFMCC membership
- Moravian Northern Province membership
- Moravian Southern Province membership
- Struckmeyer, Kurt. "Mainline Christianity. " Following Jesus Web: 13 Dec 2009
- Molly Oshatz, "The Problem of Moral Progress: The Slavery Debates and the Development of Liberal Protestantism in the United States," Modern Intellectual History, Aug 2008, Vol. 5 Issue 2, pp 225-250
- U. S. Religious Landscape Survey: Religious Beliefs and Practices, Diverse and Politically Relevant. Washington D. C.: Pew Forum on Religion and Public Life. June 2008. Web: September 27, 2009 at Pew Forum Report 2008.
- Michael G. Thompson, "An Exception to Exceptionalism: A Reflection on Reinhold Niebuhr's Vision of "Prophetic" Christianity and the Problem of Religion and U.S. Foreign Policy, " American Quarterly, Volume 59, Number 3, September 2007, pp. 833-855
- Gary Dorrien, The Making of American Liberal Theology: Crisis, Irony, and Postmodernity, 1950–2005 (2006)
- Hout, Greeley, and Wilde, "The Demographic Imperative in Religious Change in the United States," (2001) p 493
- Tenny-Brittian, Bill. "Why the Mainline is Shrinking. " Church Solutions, 04/02/2009. Web:
- Hout, Greeley, and Wilde, "The Demographic Imperative in Religious Change in the United States," (2001)
- Hout, Greeley, and Wilde, "The Demographic Imperative in Religious Change in the United States," (2001) p 494-5
- "Report 1: Religious Affiliation, " The Pew Forum on Religion & Public Life, 2009. Web: 13 Dec. 2009
Further reading 
- Ahlstrom, Sydney E. A Religious History of the American People (1976; 2004) excerpt and text search
- Balmer, Randall. Grant Us Courage: Travels along the Mainline of American Protestantism (1996) online edition
- Balmer, Randall, and Fitzmier, John R. The Presbyterians (1993). 274 pp. survey by two scholars
- Coffman, Elesha. The Christian Century and the Rise of Mainline Protestantism (Oxford, 2013)
- Billingsley, K. L. From Mainline to Sideline: The Social Witness of the National Council of Churches (1991)
- Coalter, Milton J.; Mulder, John M.; and Weeks, Louis B., eds. The Mainstream Protestant "Decline": The Presbyterian Pattern. (1990). 263pp.
- Dorrien, Gary. The Making of American Liberal Theology: Imagining Progressive Religion, 1805–1900 (2001); The Making of American Liberal Theology: Idealism, Realism, and Modernity, 1900–1950 (2003); The Making of American Liberal Theology: Crisis, Irony, and Postmodernity, 1950–2005 (2006).
- Edwards, Mark. The Right of the Protestant Left: God's Totalitarianism (Palgrave Macmillan, 2012)
- Hutchison, William R. ed. Between the Times: The Travail of the Protestant Establishment in America, 1900-1960 (1990) excerpt and text search
- Lantzer, Jason S. Mainline Christianity: The Past and Future of America's Majority Faith (2012) excerpt and text search
- Marty, Martin E. "The Establishment That Was, " Christian Century November 15, 1989, p. 1045. online
- Marty, Martin E. Modern American Religion, Volume 3: Under God, Indivisible, 1941-1960 (1999)
- Murchison, William. Mortal Follies: Episcopalians and the Crisis of Mainline Christianity (2009)
- Roof, Wade Clark, and William McKinney. American Mainline Religion: Its Changing Shape and Future (1990) excerpt and text search
- Tipton, Steven M. Public Pulpits: Methodists and Mainline Churches in the Moral Argument of Public Life (2008) excerpt and text search
- Utter, Glenn H. Mainline Christians and U.S. public policy: a reference handbook (2007)
- Wuthnow, Robert, and John H. Evans, eds. The Quiet Hand of God: Faith-Based Activism and the Public Role of Mainline Protestantism, (2002), 430 pp.; essays by scholars