The Congregational Christian Churches were a Protestant Christian denomination that operated in the U.S. from 1931 through 1957. On the latter date, most of its churches joined the Evangelical and Reformed Church in a merger to become the United Church of Christ. Others created the National Association of Congregational Christian Churches. During the forementioned period, its churches were organized nationally into a General Council, with parallel state conferences, sectional associations, and missionary instrumentalities. Congregations, however, retained their local autonomy and these groups were legally separate from the congregations.