Employing a multidisciplinary methodology using history, sociology, and theology, Gillis describes and analyzes the experiences of Catholics in America from the seventeenth century to the present. With quotations from ordinary believers, theologians, historians, bishops, and other authorities woven throughout the book, he deftly explores the interplay between worldwide Catholicism and its diverse national and local expressions.

In particular, Gillis elucidates the persistent tension between Rome and the American church, which has been shaped by a thoroughly modern, dynamic, and secular culture.

Offering a wealth of information about church membership and ethnic and geographical makeup, the book explores how Catholic views on issues such as human life, abortion, poverty, and American culture have profoundly affected political and moral discourse in the United States. A chronology, glossary, profiles of prominent American Catholics, annotated bibliography, and a list of electronic resources are also included.