At the center of American religious freedom is the claim that “Congress shall make no law respecting an establishment of religion,” which appears in the Constitution's First Amendment. It is, of course, a deceptively simple phrase. Where did such an idea come from? What has it meant to Americans throughout their history? T. Jeremy Gunn and John Witte have compiled a fine collection of thirteen essays that explore the rich and complicated history behind that clause, including essays by historians Ralph Ketchum and Daniel Dreisbach, theologian Martin Marty, law professors Steven K. Green and Thomas C. Berg, and federal judge Michael McConnell, among many others.

Americans are familiar enough with non-establishment, but we rarely ask why there was ever an establishment of religion in the first place. Michael McConnell points out that there were important reasons for state-supported religion, both in Europe and in early America, and that “we cannot understand the depth of argument for disestablishment without understanding why reasonable men and women have though that establishment was necessary to republican government” (46). Establishment took a variety of forms: some states dictated the content of Christian doctrine, required religious tests for office, had compulsory church attendance, and Sunday closing laws. Others simply offered public support for favored congregations. Sometimes the reasons for establishment were theological, but McConnell explains that it was more often political. Both state governments and state communities felt a sense of duty to preserve certain doctrinal truths, and “to serve the interests of society by inculcating ideas that promote the public interest” (62). False doctrines were considered public health risks. Americans, after all, were free and self-governing—which did not diminish but increase the public's solemn duty to protect Christian truth.

Non-establishment prevailed, of course, primarily because of the chief architects of American religious liberty, Thomas Jefferson and James Madison. Both presented the public with a thorough philosophy of church-state relations as well as some brilliantly designed legal documents—Jefferson's Bill for Establishing Religious Freedom (1779), and Madison's Memorial and Remonstrance (1785)—both of which served as precursors to the First Amendment. They shared the same goal of disestablishment, but as Ralph Ketchum argues, the two were hardly in agreement about its purpose. Jefferson's religious liberty came from his Enlightenment-style emphasis on reason over revelation, and his hope that the philosophic meaning of Christianity would finally free itself from all forms of religiosity. Madison, however, (who had studied for the ministry in his youth) “emphasized the good influence and public utility of the religious faith” (167). For him, non-establishment allowed for a purely voluntary choice in faith, which itself ensured a more sincere pursuit of God. From the state's point of view, though, that alone was the surest way to maintain a culture of virtuous, upright citizens—the only sort of people fit for self-government.

The same went for public officials, who were protected from “religious tests” under the Constitution's Article VI. Daniel Dreisbach points out how state governments were always concerned with the faith of those in office, aware of the “important task of selecting rulers committed to protecting and nurturing religion and morality.” Those holding public power were more trustworthy if they viewed their office as ordained by God (per Romans 13), aware that He was the final judge of their actions. The prohibition against religious tests, though, was seen as useful to the moral foundations of the republic: it led to spiritual flourishing among officials and citizens alike, and “provided an indispensable support for civic virtue, social order, and political prosperity” (271).

Calling Christianity “socially useful” can make believers nervous. Who, after all, would call their faith in Jesus Christ “useful”? But such a claim was not meant to exclude its truth, at least according to Madison. The state had a God-given duty to protect religious liberty and civic reasons for encouraging spiritual life—and both things corresponded in Madison's mind. He reflected in a letter from 1819 that free government “possesses the requisite stability and performs its functions with complete success, Whilst the number, the industry, and the morality of the Priesthood, & the devotion of the people have been manifestly increased by the total separation of the Church from the State” (177).

That phrase became an important element in nineteenth century American culture. It was, as Steven K. Green called it, a “second disestablishment,” and as it grew, “it overpowered alternate understandings of disestablishment in the popular imagination” (284). American society was deeply saturated with Christianity, full of thanksgiving celebrations, election sermons, and a vast array of overtly religious behavioral laws; at the same time, people largely accepted the secular character of modern society, and often expressed it as “separation of church and state.” Few Americans saw the contradiction. Protestantism, after all, was born and raised in modernity, making it quite comfortable with compartmentalizing spiritual and public life. “Protestant” and “secular” were synonymous.

But not for Roman Catholics. The new presence of Irish and Italian Catholic immigrants was viewed with great suspicion and fear following the Civil War. As Thomas Berg points out, animosity toward Catholics was primarily political: they subscribed to an un-modern form of faith, which many viewed as essential for democracy. For this, Catholics received the brunt of “separationist” thinking in public opinion and policy, especially when they established their own “sectarian” schools. Other Catholics sought exemptions from “secular” public school activities—such as in-class readings from the King James Bible. “The proponents of the public-school approach may have honestly believed it to be nonsectarian,” Berg writes, “but it reflected deeply Protestant assumptions” (319). The infamous “school wars” became so heated in this era that 1884 presidential candidate James G. Blaine suggested an amendment to the Constitution to enshrine “separation of church and state” in the Constitution once and for all, to settle the Protestant-secular character of America from the top down.

The Amendment failed, of course, but the cultural appeal of separation endured into the twentieth century. It was made constitutional, though, in 1947, when the Supreme Court handed down the landmark case of Everson v. Board of Education. There, Justice Hugo Black finally announced that the First Amendment erected a “wall between church and state,” which must be “kept high and impregnable,” and that such separation was directly applicable to state and local governments. It became the guiding legal principle when it came to public funding for anything religious—whether Catholic or Protestant. Here began the long list of cases where the Court aggressively applied “strict separation” to every point of contact between religion and public life.

For all its strengths, book unfortunately devotes little attention to the other half of the First Amendment's religion clause: that Congress cannot respect an establishment of religion, nor can it “prohibit free exercise thereof.” It is, to be sure, a book devoted to non-establishment. But a careful look at James Madison's own words indicates that Free Exercise was the greater concern, and that the prohibition against establishment of religion was for that reason, not disestablishment per se. Still, the book is an excellent guide for anyone interested in exploring the constitutional aspects of American church history.