The movement to which the name came to be applied began in the 16th and 17th cent. in England in a revolt against the Established Church. Robert Browne published in 1582 the first theoretical exposition of Congregational principles and expressed the position of some of those separatists. Churches established on such lines were started very early in the 17th cent. in Gainsborough and Scrooby, but government opposition drove them into exile in Holland.
Not until the Protectorate did the Congregationalists make much progress. About that time the name Independents was first introduced, a term long common in Great Britain (it is still used in Wales) but seldom used in America. In 1658, when the Savoy Synod met in London, over 100 churches were represented. With the Restoration came repression for the Independents, partly relieved by the Toleration Act of 1689.
A marked tendency among English Congregationalists in the 19th cent. was toward combination in larger fellowship. Churches of this denomination formed a union in Scotland in 1812 and in Ireland in 1829; in 1831 the Congregational Union of England and Wales was established. The Congregational Union and the Evangelical Union were united in 1896. Membership in Congregational churches in Great Britain has declined in the 20th cent. Congregationalists have been active in ecumenical activities, and in 1972 most British Congregationalists and Presbyterians merged to form the United Reform Church.
Congregationalism was carried to America in 1620 by the Pilgrims, who were members of John Robinson's congregation in Holland, originally of Scrooby, England. In America, Congregationalism reached its greatest public influence and largest membership. In New England numerous communities were established based on Congregational-type religious principles. In 1648 in the Cambridge Platform a summary of principles of church government and discipline was drawn up. Congregationalists took a leading part in the Great Awakening that, in New England, was started in 1734 by the preaching of Jonathan Edwards. As the country expanded, Congregational churches were established in the newly opened frontier regions.
In 1810 the American Board of Commissioners for Foreign Missions began its work; in 1826 the American Home Missionary Society was formed. These were followed in 1846 by the American Missionary Association, primarily devoted to missionary work among African Americans and Native Americans. The early part of the 19th cent. brought the Unitarian secession, when over 100 churches left the main Congregational body.
Congregational churches began to meet in local and then in statewide conferences, out of which developed (1871) the National Council of the Congregational Churches of the United States. But each local church remained free to make its own declaration of faith and free to decide its own form of worship; in the conduct of the local church each member was granted an equal voice. The principal assistants of the pastor are the deacons. In education Congregationalists were always prominent, but the institutions of their founding—Harvard, Yale, Williams, Amherst, Oberlin, and many others—have generally been free from sectarianism.
The trend toward broader fellowship and larger cooperation was notably indicated in the merging in 1931 of the National Council of the Congregational Churches of the United States and the General Convention of the Christian Church (see Christian Church (Disciples of Christ)) to form the General Council of the Congregational and Christian Churches of the United States. A move to unite the Congregational Christian Churches with the Evangelical and Reformed Church was approved by the councils of the two denominations in 1957, forming the United Church of Christ. The National Association of Congregational Christian Churches was formed in 1955 by churches that chose not to join in the merger; it had about 70,000 members in 1997.