stay open, with little or nothing left over for mission work. Congregationalists constituted about 85-90% of the membership of the new denomination; this caused few if any resentments or conflicts because, by and large, the two groups did not overlap each other geographically, except in parts of New England, upstate New York, Ohio, and among African-American churches in North Carolina. Regional judicatories and national domestic and foreign mission agencies merged quite smoothly, often continuing to use varying terminologies (e.g., "convention," "conference," "association"), depending on custom. On the domestic front, most of the new church planting efforts were concentrated in newly developing areas such as southern California, Arizona, Florida, and suburbs of major Midwestern cities (e.g., Chicago, Detroit, Minneapolis). Abroad, many CC missionary efforts shifted their emphases toward medical and social services, particularly after many of the churches Congregationalists had founded in earlier decades had formed autonomous bodies of their own. One distinguishing trait of the new fellowship, aside from its unusually tolerant attitude regarding subscription to ancient doctrines, was its bold enthusiasm for ecumenical adventures, especially those growing out of the "Faith and Order" and "Life and Work" inter-church initiatives in Great Britain in the 1920s and 1930s. These developments and others led to the founding of the World Council of Churches in 1948, of which the Congregational Christian Churches was a charter member. In the U.S., the Congregational Christians made several overtures to other Protestant groups toward federative unions and/or organic mergers in the years before World War II. But the main legacy of those discussions was what became the United Church of Christ in 1957. UCC merger talks The Rev. Dr. Truman Douglass, pastor of St. Louis' Pilgrim Congregational Church, met with the Rev. Dr. Samuel Press, president of Eden Theological Seminary in that city, a seminary of the Evangelical and Reformed Church, a denomination predominantly of German origin and itself a merger of two previously separated traditions, as part of an informal interchurch discussion group in 1937. Douglass' and Press' talks led to the involvement of both bodies in proposals to consider organic union, work that eventually culminated in the Basis of Union in 1943, which both national bodies approved after a five-year period of revising. The Rev. Dr. Douglas Horton, a former Harvard Divinity School dean, had become the CC general minister and president by this point, and became the prime figure in the CC union