Since its original release in 1939, Carl Schneider's The German Church on the American Frontier has been the premier published resource on the unique "Evangelischer Kirchenverein des Westens" (Evangelical Church Society of the West), 1840-66, which later assumed a wider denominational identity as the German Evangelical Synod of North America, the church of the Niebuhr family. Known eventually as the Evangelical Synod of North America, the group's ecumenical and irenic heritage contributed to mergers that resulted in the Evangelical and Reformed Church, 1934-1957, and thereafter in the United Church of Christ.