Only rarely does a scholar earn the informal title of “dean” of his or her particular specialty, but that honor was surely merited by John Tracy Ellis (1908–92). Over a long career, Ellis was recognized as the leading figure in the study of the history of the Roman Catholic Church in the United States. His own substantial scholarship – a dozen major books, several seminal articles, a three-volume collection of primary documents, decades of editing the Catholic Historical Review – together with the successive generations of younger historians whom he taught (not to mention future members of the hierarchy) gave him an unrivaled influence. Today, his work can seem old fashioned. A two-volume biography of a single bishop, even an important one – Ellis's The Life of James Cardinal Gibbons, longtime archbishop of Baltimore and friend of Theodore Roosevelt, appeared in 1952 – would never make it to publication now. But his steady output helped open the doors to a broader historiographical enterprise, moving Catholic history decisively out of the realm of apologetics and into more sophisticated social and cultural analysis.

Thomas Shelley, a former student who became a professor of history at Fordham University, has published a full biography, drawing on Ellis's extensive correspondence and an unpublished autobiography. A scholar's life of teaching and writing can seem uneventful but, in addition to describing the academic career, Shelley also focuses on two areas of larger concern. The first was Ellis's sustained interest in promoting the intellectual life of the American Catholic community. A 1955 essay prompted what one participant called a “warm discussion” about how Catholics had failed to match their evident social and economic progress with contributions to the world of ideas. Too much focus on institution-building, he said, and too little interest in the life of the mind on the part of church leaders, a product of woefully inadequate seminary training, kept Catholics out of the American mainstream. Bishops had not been accustomed to hearing such criticism, especially from one of their own, but Ellis had provided a manifesto that the leaders of Catholic colleges and universities could use to bring their institutions more into line with the rest of American higher education.

The other charts his participation in the swirl of church reform that came in the aftermath of the Second Vatican Council (1962–65). Ellis was an ardent supporter of change, and this provides the justification for the characterization of him in Shelley's subtitle as a reformer. The path was not always rosy. Ellis spent more than a decade – a one-year sabbatical turned into thirteen – in a kind of exile from his base at Catholic University in Washington after a dispute with the administration there over academic freedom. He was dismayed when some of the leading international reformers were barred from speaking on campus. A few years later, when a priest in the theology department was summarily dismissed for his dissent over the reaffirmation of the church's traditional position on contraception in the papal encyclical Humanae Vitae (1968), Ellis began to wonder whether the institution where he had spent most of his adult life was a place where he could stay. By the time he returned, the mental climate was a very different one, and he went on to argue for further changes, not always successfully. He was apparently even open to the quixotic idea of allowing some role for lay people in the selection and appointment of bishops. He also provided a very important service to historians, one that goes unmentioned by Shelley. Ellis was the principal author of a short document, published at the time of the run-up to the Bicentennial celebrations of 1976, urging the establishment of formal, professionally managed archives programs to preserve and make accessible the records of the church in this country. A positive explosion of archival activity among dioceses and communities of religious women and men ensued, and historians everywhere are still its beneficiaries.

Shelley, a highly productive scholar himself, died shortly after the book appeared, and it therefore stands as a kind of homage to both men. It is an important contribution to the history of history.