Conkin defines Reformed Christianity broadly, to encompass all denominations originating in the work of reformers other than Luther, including Calvin, Zwingli, Cranmer, and Knox. During the colonial period and the first century after independence, these Reformed denominations - most notably Presbyterians, Episcopalians, Congregationalists, Methodists, and Calvinist Baptists - made up by far the largest and most influential segment of Christianity in America.

Conkin portrays growing unease and conflict within this center of American Protestantism before the Civil War. Scholarly and scientific challenges to evangelical Christianity constituted a threat from without, while disagreements over strictly religious issues or sectional differences related to the issue of slavery weakened the mainstream from within.

Doctrine, especially regarding salvation, was the most important basis of denominational identity, Conkin argues, and was therefore a central element in conflict and competition between Reformed denominations. Institutional practices also exacerbated differences, and Conkin examines how various churches governed themselves and how they selected, trained, and ordained clergy.

In The Uneasy Center, distinguished intellectual historian Paul Conkin offers the first comprehensive examination of mainline Protestantism in America, from its emergence in the colonial era to its rise to predominance in the early nineteenth century and the beginnings of its gradual decline in the years preceding the Civil War. He clarifies theological traditions and doctrinal arguments and includes substantive discussions of institutional development and of the order and content of worship.