Historian Butler’s God in Gotham (Belknap, Aug.) explores the rise of religious pluralism in Manhattan between 1880 and 1960.

What prompted you to write about the growth and spread of religion in Manhattan?

Manhattan was the ideal location for a book on the fate of religion in America’s mushrooming cities between the 1880s and the 1960s. Manhattan put forward two contradictory images about religion: many saw it as the epitome of modern American secularism, yet it exhibited the nation’s most bountiful example of Protestant, Jewish, and Catholic religious pluralism. How did these traditional religious groups, both Judaism and Catholicism fueled by massive immigration to the city between 1880 and 1910, grapple with the press of modernity and urban density to survive? Rather than reject modernity, they embraced virtually all the techniques of modernity to confront Manhattan’s urban prospect head-on, producing a city teeming with religion, filled with sanctuaries crowded with worshippers and birthing a remarkable urban theological hothouse.

There is an incredible amount of detail in this book. What was your research process like?

Much in the book represents very traditional research in archives and libraries accomplished over a number of years. These include personal diaries and obscure religious publications, as well as denominational records. But the accelerating availability of digitized materials through the internet transformed my research—scarce denominational records, obscure books available in only a few libraries, and long-forgotten religious publications most readers discarded became available online. The digitization of newspapers represented the greatest gain. Newspapers reported extensively on Manhattan’s religious doings, events, and controversies. Being able to locate them through keyword searches rather than laboriously searching by hand through paper copies unearthed materials that even decades of hand-searching would never have produced.

What message does the book have for urban centers today?

Religiosity can prosper vividly in urban settings, not merely survive. Not all urban settings replicate those present in Manhattan between the 1880s and the 1960s. Each would be distinctive. But the common features of urban centers in most places in the U.S. and the world—high density, deep institutional complexity, population diversity, and implicit religious pluralism—no more precludes religious vigor and commitment in today’s world than did Manhattan between the 1880s and the 1960s.