[1] The Reformed tradition was and remains centered in Pennsylvania, particularly the eastern and central counties of that state, and extends west to Ohio and Indiana and south to Maryland, Virginia, and North Carolina in the first generation of immigration.

Some of the more radical practitioners of revivalism and/or pietism defected to Brethren bodies; still others formed the Churches of God, General Conference, a conservative, doctrinally Arminian group.

Named for Mercersburg, Pennsylvania, where the Reformed seminary was located in the mid-19th century, scholarly and ministerial advocates of this position sought to reclaim an older, European sense of the church as a holy society that understood itself as organically related to Christ.

This implied a recovery of early Protestant liturgies and a renewed emphasis upon the rite of Holy Communion, somewhat akin to the Tractarian or Anglo-Catholic movement in Anglicanism but within a Reformation vein.

This group, centered in southeastern Pennsylvania in close proximity to a large Catholic population in Philadelphia and thus motivated by Anti-Catholicism, objected strenuously to the Mercersburg reforms, going so far as to establish a separate seminary now known as Ursinus College.

The convictions of some members were so strong that a few churches in that group, most of which were in South Dakota, defected immediately prior to the 1934 merger, influenced by such strict confessionalism, a belief in biblical inerrancy, and a fear of losing their Reformed roots.

[2] This schism aside, by the time of the merger talks, the RCUS had mostly joined the American Protestant mainline, sending missionaries overseas and operating health and welfare institutions, including hospitals, orphanages, and nursing homes, throughout much of the United States.

Although their faith was chiefly the product of a forced union by the government in Prussia, the Evangelicals by conviction wished to minimize the centuries-old points of contention between Lutheran and Reformed doctrine and practice.

This attitude of moderation was enabled in large measure by the rise of pietism, which stressed a more emotional, less rationalistic approach to the teachings of the Bible, thus disinclining scholars and pastors toward technicalities or polemics.

Many Evangelical parishes were founded by pastors trained in interdenominational missionary societies such as the St. Chrischona Pilgrim Mission in Basel, Switzerland, in the early 19th century; they immigrated to the United States to assist settlers fleeing Prussian militarism.

[3] In terms of governance, the Evangelicals most resembled American Lutheranism of the time, with high regard for the pastor's authority but essentially congregational in structure, with a lay council handling temporal matters such as property and benevolences.

Styles of worship ranged from revivalism (especially in Ohio and North Carolina) to a Lutheran-like liturgicism (the Mercersburg Movement found primarily in central Pennsylvania parishes).

Generally speaking, the theological outlook of most ministers was largely accepting of liberal trends in Protestant doctrine and higher biblical criticism, although some pockets of conservative revivalistic pietism and confessionalist Calvinism could be found.