UPCUSA

United Presbyterian Church in the United States of America
Classification	Protestant
Theology	Reformed
Polity	Presbyterian
Region	United States
Origin	May 28, 1958 Pittsburgh
Merger of	The Presbyterian Church in the United States of America (the "Northern Presbyterians") and the United Presbyterian Church of North America
Separations	Evangelical Presbyterian Church (EPC) in 1981
Merged into	The Presbyterian Church (U.S.A.) (1983)
Members	2,351,119 in 1982

The United Presbyterian Church in the United States of America (UPCUSA) was the largest branch of Presbyterianism in the United States from May 28, 1958 to 1983. It was formed by the union of the Presbyterian Church in the United States of America (PCUSA), often referred to (inaccurately) as the "Northern" Presbyterian Church, with the United Presbyterian Church of North America (UPCNA), a smaller church of Covenanter-Seceder tradition at a conference in downtown Pittsburgh, Pennsylvania in May 1958. Vigorous ecumenical activity on the part of PCUSA leaders led to this merger, something of a reunion of two long-separated branches of the larger Presbyterian family deriving from the British Isles.

Between 1937 and 1955, both the Presbyterian Church in the United States of America, and the United Presbyterian Church of North America had been looking to merge with Reformed Churches. The PCUSA had discussed a merger with the Presbyterian Church in the United States (PCUS), as well as with the Episcopal Church. Both denominations had also been in contact with the Reformed Church in America, as well as the Associate Reformed Presbyterian Church.

By the time of the merger, the PCUSA had churches in all 50 states, while the heaviest concentration of UPCNA congregations could be found in Western Pennsylvania and parts of Ohio. One institutional expression of the union was the consolidation of two nearby seminaries into the new Pittsburgh Theological Seminary.

...
Wikipedia