Floods of immigration and rapid industrialization and urbanization in America at the turn of the century set in motion the transformation of many long-established institutions. This book examines specific ways in which cultural changes affected the structure of the religious establishment. Statistical models are applied to United States Census data from 1890 and 1906 on city and church populations, revealing connections between the growth of cities, the increase in literacy, and the formation of ethnic subcommunities that led to a new level of religious diversity. The author analyses evidence of growing competition among churches and of a level of individual commitment to congregations, demonstrating that the patterns of religious community established at the turn of the century provided the basis for the current denominational system. The author further analyses the relationship of religious diversity to urban secularization, as well as its role as a catalyst to sectarian conflict. In offering a quantitative assessment of issues central to the history of American religion, this book is a significant contribution to the study of religion in America.

More than 450 years after their birth in the Anabaptist movement, 125 years after their secession from Russian Mennonitism, and 60 years after their immigration to Canada, the Mennonite Brethren exhibit specific and measurable signs of sectarian viability and religious vitality. To explain the persistence of the sect, Hamm analyses the process of sacralization within the Canadian Mennonite Brethren Church — which “safeguards identity, a system of meaning, or a definition of reality” — and the process of secularization — which “erodes boundaries, dislodges stable structures, and destroys identity.” It is an oversimplification, the author argues, to insist that the factors of continuity — ethical and cognitive norms, family solidarity, ethnicity, worship, evangelism, community and church structures, and service agencies — are solely integrative and that the factors of change — urbanization, education, occupational change, and economic affluence — are solely disruptive. Instead, a complex dialectic between the two processes is at work that prevents restrictive rigidity within the sect and excessive accommodation to the host society. According to the author, “this analysis of the Canadian Mennonite Brethren becomes a case study to test the utility of an identity theory of religion, which hinges on the integration/differentiation dialectic. It is, at the same time, a serious self-study in religious sociology, by which the author seeks to gain a better understanding of the processes of growth and decline, of continuity and change, and of the ongoing tension resulting from the religious movement’s confrontation with society.”

In the first book ever written on the subject, Carl Bowman examines how and why members of the Church of the Brethren—historically known as "Dunkers" after their method of baptism—were assimilated faster and earlier than their Amish, Mennonite, or even Hutterite cousins.