Beginning in 1942, in response to liberal trends in the PCUS, conservative churchmen such as L. Nelson Bell, longtime medical missionary to China and father-in-law of evangelist Billy Graham, began establishing various periodicals and renewal parachurch organizations for conservative clergy and laymen alike. In 1966, conservatives founded Reformed Theological Seminary in Jackson, Mississippi. Eventually, in December 1973, prompted both by liberalism, and a proposed "Plan of Union" between the UPCUSA and the PCUS which reportedly had not included an escape clause for congregations that had no desire of being part of the planned denomination, delegates from 260 churches met in Birmingham, Alabama to form the National Presbyterian Church, which would later be renamed the Presbyterian Church in America in 1974.