American Baptist Churches USA  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 2017, ABCUSA had 1,145,647 members in 5,057 congregations. 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.