The American Baptist Churches USA ( ABCUSA ) is a Baptist Christian denomination within the United States. The denomination maintains headquarters in Valley Forge , Pennsylvania . The organization is usually considered mainline , although varying theological and mission emphases may be found among its congregations, including modernist, charismatic and evangelical orientations. It traces its history to the First Baptist Church in America (1638) and the Baptist congregational associations which organized the Triennial Convention in 1814. From 1907 to 1950, it was known as the Northern Baptist Convention, and from 1950 to 1972 as the American Baptist Convention .
In 2014, ABCUSA had 1,198,046 members in 5,120 congregations.
Colonial New England Baptists
The Puritan minister Roger Williams ( c. 1603–1683) established the First Baptist Church in Providence — now the First Baptist Church in America — in 1638. Regarded by the more dogmatic Puritans of the Massachusetts Bay Colony as a heretic for his religious separatism , Williams was banished into the New England wilderness where he and his followers created the settlement of Providence and later, the colony of Rhode Island . Williams is credited with being the founder of the Baptist movement in America, the founder of the state of Rhode Island, and the first highly visible public leader in America to call for the separation of church and state .
Having a congregational polity , early Baptist churches in America operated independently from one another, following an array of Protestant theological paths, but were often unified in their mission to evangelize. In the 18th century, they sometimes created local congregational associations for support, fellowship, and work (such as the founding of Brown University in 1764). The evangelical mission led to the establishment of the national Triennial Convention in 1814, a collaborative effort by local churches to organize, fund, and deploy missionaries. The ABCUSA descends from this Triennial Convention. Through the Triennial Convention structure a number of mission-oriented societies were formed, including the American Baptist Foreign Mission Society (1814), American Baptist Home Mission Society (1832), American Baptist Publication Society (1841), and the American Baptist Education Society (1888).
In 1845 a majority of Baptists in the South withdrew support from the Triennial Convention — largely in response to the decision of its delegates to ban slave holders from becoming ordained missionaries — and formed the Southern Baptist Convention (SBC). The Triennial Convention was loosely structured, and the SBC offered Baptists a more centralized organizational structure for carrying on missionary and benevolent work. In contrast, however, the Triennial Convention afforded local churches a higher degree of local autonomy, a more traditional characteristic of Baptist polity. The majority of churches in the North continued to work through these separate cooperating societies for missions and benevolence. The societies were united under the umbrella of a unified convention in 1907.
Northern Baptist Convention
The Northern Baptist Convention was founded in Washington, D.C. on May 17, 1907. Charles Evans Hughes , the then sitting governor of New York and later Chief Justice of the United States , served the body as its first president. The purpose of the Northern Baptist Convention was to bring about a consistent cooperation among the separate Baptist bodies then existing. It was the first step in bringing together Baptists in the North "with ties to the historic American Baptist mission societies in the nineteenth century."  These had contributed to establishing many schools for freedmen in the South after the American Civil War , as well as working on issues of health and welfare. Many of their missionaries and members had worked as teachers in the South. In 1911, most of the churches of the Free Will Baptist General Conference merged with it.
American Baptist Convention
The name of the Convention was changed in 1950 to the American Baptist Convention (ABC), and it operated under this name until 1972. It was the second step at bringing together on a national level Baptists with ties to the mission societies. The ABC was characterized from 1950–66 with annual resolutions at its conventions having to do with the Civil Rights Movement and race relations.
Without exception, these resolutions were progressive and genuinely encompassing. They addressed both the need for individual change in attitude and action, and the need for broader social change that could only be instituted through political action. 
As in many cases, the rhetoric of the annual conventions was sometimes ahead of local activity, but the denomination gradually made progress. In 1964 it created the Baptist Action for Racial Brotherhood (BARB), which early the next year produced a pamphlet outlining actions for change in local churches. In 1968 the national convention was challenged by "Black American Baptist Churchmen Speak To the American Baptist Convention," demands that challenged how the denomination had "conducted its business relative to black American Baptists."  The black churchmen said the Convention had excluded them from decisionmaking positions, even while working with good intentions on behalf of black American Baptists. The following year, Dr. Thomas Kilgore Jr., pastor of the Second Baptist Church of Los Angeles, was elected the first black president of the Convention. The 1968 Convention also voted to create the Study Commission on Denominational Structure (SCODS). Its recommendations changed the denomination in a variety of ways, after being adopted at the 1972 Convention. 
American Baptist Churches USA
To reflect its new structure, the Convention in 1972 changed its name to the American Baptist Churches USA. Rather than relying on decisionmaking at the annual Convention by whichever churches happened to send delegates, the SCODS restructuring resulted in the following:
A General Board was composed of duly elected representatives from geographically designated districts. Three-fourths of those representatives would be elected by the American Baptist regional bodies; one-fourth would be elected as at-large representatives, or in the official terminology, "Nationally Nominated Representatives." These representatives would be "chosen so as to provide the necessary balance among the Representatives in respect of racial/ethnic inclusiveness, geographic area, age, gender, and desirable skills. 
In 2006, the American Baptist Churches of the Pacific Southwest, believing that "the practice of homosexuality is incompatible with Christian teaching," split from the ABCUSA. The region was renamed Transformation Ministries .  This happened notwithstanding the fact that the ABCUSA affirms that each congregation possesses the freedom to determine whether or not to perform same-sex marriages or ordain LGBT clergy. 
Theology and practice
American Baptists believe that the Bible is the inspired word of God and the final authority in matters of faith.  The ABCUSA affirms the Trinity , that the one God exists as three persons in complete unity: God the Father , God the Son , and God the Holy Spirit . They confess Jesus Christ as Savior and Lord through whom those who believe can have fellowship with God. He died, taking on the sins of the world, and was resurrected, triumphing over sin and death. 
ABCUSA churches recognize two ordinances: Believer's baptism and the Lord's Supper . Baptism is by immersion, and those being baptized must be of an age to understand its significance. Believing in the priesthood of all believers , the ABCUSA avoids using creeds, affirming the freedom of individual Christians and local churches to interpret scripture as the Holy Spirit leads them. The ABCUSA affirms the ordination of women . 
Regarding issues of human sexuality, the ABCUSA is consistent in its approach and allows each congregation to determine whether or not to perform same-sex marriages or ordain LGBT clergy.  The ABCUSA General Board voted in 2005 to amend the statement "We Are American Baptists" to define marriage as "between one man and one woman" and declare that "the practice of homosexuality is incompatible with Biblical teaching."  However, the denomination also stated that it will "respect and will continue to respect congregational freedom on this issue".  So, each local congregation is autonomous and permitted to perform same-sex marriages if they opt to do so.  For example, Calvary Baptist Church in D.C., affiliated with the ABCUSA, performs same-sex marriages.  In 2013, an ABCUSA congregation in Washington D.C., ordained the denomination's first openly transgender pastor. 
The American Baptists Churches USA has a congregationalist polity emphasizing local church autonomy. Local churches are organized into 33 regions. The General Board makes policy for the denomination's national agencies.  However, General Board resolutions are not binding on local congregations. Three-fourths of the representatives to the General Board are nominated and elected by the regions. One-fourth of the representatives are nominated by the Nominating Committee and are elected by the regions. The General Secretary executes the policies and decisions of the General Board. Rev. Dr. Lee B. Spitzer was called as ABCUSA General Secretary on May 8, 2017.
A substantial portion of the ABCUSA consists of African-American churches that may have joint affiliations with the ABCUSA and historic bodies such as the National Baptist Convention or the Progressive National Baptist Convention .
In 2009, the ABCUSA reported 1,310,505 members in 5,402 churches.  Membership remained fairly steady during the 20th century. In 1925, there were just over 1.4 million members. Membership peaked in the early 1980s at around 1.6 million.  Lately, membership has begun to decline again, with the ABCUSA reporting 1,198,046 members in 5,120 churches at the end of 2014.  Congregations are concentrated in the Midwest and Northeast United States. 
There are a number of universities and colleges affiliated with the ABCUSA . There are ten seminaries affiliated with the American Baptist Churches USA:
- American Baptist Seminary of the West , Berkeley, California
- Andover Newton Theological School , Newton, Massachusetts
- Central Baptist Theological Seminary, Shawnee, Kansas
- Colgate Rochester Crozer Divinity School , Rochester, New York
- Evangelical Seminary of Puerto Rico , San Juan, Puerto Rico
- Morehouse School of Religion , Atlanta, Georgia
- Northern Baptist Theological Seminary , Lombard, Illinois
- Palmer Theological Seminary , King of Prussia, Pennsylvania
- Shaw University Divinity School , Raleigh, North Carolina
- The Samuel DeWitt Proctor School of Theology, Virginia Union University , Richmond, Virginia
- Includes Northern Baptists (1907-1950) and American Baptists (1950-present)
- Wayland Hoyt (1838-1910), minister and author
- John D. Rockefeller (1839–1937), oil magnate and philanthropist
- Charles Evans Hughes, Sr. (1862–1948), 36th Governor of New York , 11th Chief Justice of the United States , and first president of the Northern Baptist Convention
- John D. Rockefeller Jr. (1874-1960), financier and philanthropist