As cofounder of the website Killing the Buddha in 2000, Peter Manseau helped pioneer religion journalism online; as a memoirist in Vows: The Story of a Priest, a Nun, and Their Son (Free Press, 2006) he chronicled his parents’ lives as a window into mid-century American Catholicism; and as a novelist he won a National Jewish Book Award with Songs for the Butcher’s Daughter (Free Press, 2008), a story about the disappearance of Yiddish culture.

Now with a Ph.D. in religion from Georgetown University, Manseau has published One Nation, Under Gods: A New American History (Little, Brown, Jan.). In a starred review, PW called it “engagingly written, with a historian’s eye for detail and a novelist’s sense of character and timing.” PW talked with Manseau about what he calls a “new story about American religion.”

What prompted you to write One Nation, Under Gods?

Several years ago we were in the midst of this moment where there was so much public argument about whether the United States was founded as a Christian nation. Most books argued for one side or the other, so I wanted to offer something non-polemical that captured the diversity and individuality that has always characterized American religion.

Your book argues that America’s religious character is shaped by what’s outside the mainstream story. What do you mean?

Whereas any creative pursuit, like art and music, has been shaped by the margins of culture, we for some reason have assumed that religion has been shaped from the center and the mainstream. But the mainstream has always been influenced by the margins, even from the outset.

Your book is ambitious in covering 500 years of American religious history in one volume. How did you do it?

As a memoirist and a novelist, I wanted this to be a story about individuals. I wanted to cover 500 years of history in 18 chapters, roughly one for each generation. Ideally within each chapter and generation I would focus on one individual who could represent the discussions and ideas and problems of that time.

How did you find these people?

I had a general sense of the types of the stories I hoped to find and include. For Mary Moody Emerson, I started with Ralph Waldo Emerson and transcendentalism. I began to notice how Emerson mentions his eccentric aunt, so the next step was to track down her own writing. This woman who was very pious and would have called herself an orthodox Christian was also part of a movement toward expanding America’s religious diversity through her interest in India.

This book took you four years to research and write. Can you describe the process?

My writing really began in newspaper archives. Fortunately for me, those are digital. What I like to do in the writing is focus on particular moments, particular scenes, but then always refocus at the end on the main character. You have the individual, the personal concern, but that is part of a much bigger picture. You start small, then pull back for the wider context, then refocus on the individual person.

Who is the audience for this book?

Each of my earlier books has appealed to a particular subculture of readers. My memoir was very Catholic; my novel was very Jewish. But what I wanted to do in writing this book was join together all these subcultures and put them in a larger frame. I hope it will find a broader readership than my previous books have had, but will also appeal to those specialized interests.