Information:  - Pittsburgh is a city in the Commonwealth of Pennsylvania in the United States, and is the county seat of Allegheny County. The Combined Statistical Area (CSA) population of 2,659,937 is the largest in both the Ohio Valley and Appalachia, the second-largest in Pennsylvania after Philadelphia and the 20th-largest in the U.S. Located at the confluence of the Allegheny and Monongahela rivers, which form the Ohio River, Pittsburgh is known as both "the Steel City" for its more than 300 steel-related businesses, and as the "City of Bridges" for its 446 bridges. The city features 30 skyscrapers, two inclines, a pre-revolutionary fortification and the Point State Park at the confluence of the rivers. The city developed as a vital link of the Atlantic coast and Midwest. The mineral-rich Allegheny Mountains made the area coveted by the French and British empires, Virginia, Whiskey Rebels, and Civil War raiders.  - 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.  - The British Isles are a group of islands off the north-western coast of continental Europe that consist of the islands of Great Britain, Ireland and over six thousand smaller isles. Situated in the North Atlantic, the islands have a total area of approximately 315,159 km, and a combined population of just under 70 million. Two sovereign states are located on the islands: Ireland (which covers roughly five-sixths of the island with the same name) and the United Kingdom of Great Britain and Northern Ireland. The British Isles also include three Crown Dependencies: the Isle of Man and, by tradition, the Bailiwick of Jersey and the Bailiwick of Guernsey in the Channel Islands, although the latter are not physically a part of the archipelago.  - Presbyterianism is a part of the Reformed tradition within Protestantism which traces its origins to Scotland.  - The United Presbyterian Church of North America (UPCNA) was an American Presbyterian denomination that existed for one hundred years. It was formed on May 26, 1858 by the union of the Northern branch of the Associate Reformed Presbyterian Church (Covenanter and Seceder) with the Associate Presbyterian Church (Seceders) at a convention at the Old City Hall in Pittsburgh. On May 28, 1958, it merged with the Presbyterian Church in the United States of America (PCUSA) at a conference in Pittsburgh to form the United Presbyterian Church in the United States of America (UPCUSA).  - Presbyter (Greek , : "elder" or "priest" in Christian usage) in the New Testament refers to a leader in local Christian congregations, with presbyter being from the Greek ""presbyteros"" and meaning elder/senior and episkopos meaning overseer, referring exclusively to the office of bishop, but with presbyteros being understood by many as referring to the same person functioning as overseer. In modern Catholic and Orthodox usage, presbyter is distinct from "bishop" and synonymous with "priest". However, in predominant Protestant usage, the term is not seen as referring to a member of a distinctive priesthood called "priests," but instead terms such as "minister", "pastor" and "elder" are used.  - The Presbyterian Church in the United States (PCUS, originally Presbyterian Church in the Confederate States of America) was a Protestant Christian denomination in the Southern and border states of the United States that existed from 1861 to 1983. That year it merged with the United Presbyterian Church in the United States of America (UPCUSA) to form the Presbyterian Church (USA).  - The Presbyterian Church in the United States of America ( PCUSA ) was the first national Presbyterian denomination in the United States , existing from 1789 to 1958 . In 1958 , the PCUSA merged with the United Presbyterian Church of North America , a denomination with roots in the Seceder and Covenanter traditions of Presbyterianism . The new church was named the United Presbyterian Church in the United States of America . It was a predecessor to the Presbyterian Church ( USA ) . The denomination had its origins in colonial times when members of the Church of Scotland and Presbyterians from Ireland first immigrated to America . After the American Revolution , the PCUSA was organized in Philadelphia under the leadership of John Witherspoon to provide national leadership for Presbyterians in the new nation . In 1861 , Presbyterians in the Southern United States split from the denomination because of disputes over slavery , politics , and theology precipitated by the American Civil War . The Southern churches established the Presbyterian Church in the United States , often simply referred to as the `` Southern Presbyterians '' . Due to its regional identification , the PCUSA was commonly described as the Northern Presbyterian Church . Despite the PCUSA 's designation as a `` Northern church '' , it was once again a national denomination in its later years . The church 's doctrines and practices were more ecumenical and less committed to traditional Calvinism , having been influenced by Arminian beliefs early in the 19th century , liberal theology late in the 19th century , and neo-orthodoxy by the mid- 20th century . The theological tensions within the denomination were played out in the Fundamentalist -- Modernist Controversy of the 1920s and 1930s , a conflict that led to the development of Christian fundamentalism and has historical importance to modern American Evangelicalism . Conservatives dissatisfied with liberal trends left to form the Orthodox Presbyterian Church in 1936 .  - The Associate Reformed Presbyterian Church (ARPC), as it exists today, is the remnant of a small denomination, which was formed from the Synod of the South, a division of the Associate Reformed Church. The original Associate Reformed Church resulted from a merger of the Associate Presbytery (from the Seceder tradition of the 18th century) and most of the Reformed Presbytery (from the Covenanter tradition of the 17th century) in Philadelphia in 1782. It is one of the oldest of the United States' theologically and socially conservative denominations.  - A Christian denomination is a distinct religious body within Christianity, identified by traits such as a name, organisation, leadership and doctrine. Individual bodies, however, may use alternative terms to describe themselves, such as church or sometimes fellowship. Divisions between one group and another are defined by authority and doctrine; issues such as the nature of Jesus, the authority of apostolic succession, eschatology, and papal primacy may separate one denomination from another. Groups of denominations  often sharing broadly similar beliefs, practices, and historical ties  are sometimes known as "branches of Christianity" or "denominational families".  - The Presbyterian Church (USA), or PC(USA), is a mainline Protestant Christian denomination in the United States. A part of the Reformed tradition, it is the largest Presbyterian denomination in the U.S., and known for its relatively progressive stance on doctrine. The PC(USA) was established by the 1983 merger of the Presbyterian Church in the United States, whose churches were located in the Southern and border states, with the United Presbyterian Church in the United States of America, whose congregations could be found in every state.    Given the information, choose the subject and object entities that have the relation of 'instance of'.
Answer:
presbyterian church in the united states of america , christian denomination