It’s daunting to learn that eight American religious historians have taken the time to assess an article I wrote twenty years ago about the state of modern American religious history and to consider what’s happened since. I’m even more stunned because I don’t know several of the authors and only one is a former student.

The 2004 article was not published in the usual manner by sending an independently written essay to a journal. Rather, it was written on a commission from Joanne Meyerowitz, then editor of the Journal of American History (only later a Yale colleague). She wanted a historiographic essay on the current state of American religious history, possibly focused on the role of personal faith in writing religious history, a widely debated issue at the time. However, she made it clear that the content was entirely up to me. I thought about the personal faith issue. But I decided instead to assess the startling jack-in-the-box way religion appeared in writing modern American history. Fortunately for me, Joanne was wonderfully supportive of my proposal. We critiqued the original draft, deleted some material, changed an early title—“Spiritual Jack-in-the-Box” to a punchier “Jack-in-the-Box Faith”—and sent it to the printer.

The essay came from the surprise an early American historian like me experienced in transitioning to teaching and writing modern American history. What caught my attention was the stark difference in the way historians described religion’s place in culture and politics from the colonial period to the Civil War, then from 1865 to 2000. In the early era, religion is treated as endemic to the culture. But after the Civil War and especially after 1900, religion pops up only sporadically, then disappears, like a jack-in-the-box.

I had been discussing this jack-in-the-box phenomenon in my graduate seminars, taught jointly with my colleague Harry Stout, and my lecture course in modern American religious history. The metaphor came from my experience as a dad. When they were little, both our boys were delighted by the musical jack-in-the-box toy. It played a tune as you wound. Then, suddenly, the clown popped up. When you closed the lid, the clown disappeared. To me, it typified the way religion appeared in twentieth-century American histories, popping up in unique episodes, then disappearing, all unconnected to the larger flow of modern American life.

I was pleased by the essay’s reception. Several colleagues wrote to say how much they liked it, and no one wrote to say how wrong I was (of course, that’s not to say no one thought I was off base, just that they didn’t write). When I’d see a reference to it in someone else’s article in the next few years, I realized it also was enjoying a longer shelf life than other articles I’d written. Seeing references to it a decade and more later, I admit I paid less and less attention. Life goes on.

I’ve never been one to rethink work I’ve published, so rereading “Jack-in-the-Box Faith” two decades after it appeared was sometimes jolting. I was disappointed by too many convoluted sentences. And yes, if I were writing it today, I’d leave a few things out and add others. But I see what I did and am glad I wrote it. I think the main points were accurate and that a deeper understanding of religion as an endemic part of twentieth-century American life is critical to understanding modern America. Indeed, at least for me, religion’s role in twenty-first-century American politics and culture reinforces the point. Donald Trump and his evangelical supporters aren’t jacks-in-the-box. Failing to understand this has proven very, very costly.

The eight essays unanimously record a remarkable wealth of historical scholarship about twentieth- and twenty-first-century American religion, culture, and politics published in the last twenty years. The sheer volume is impressive on any scale. But it’s the wild variety of work that’s really interesting. It makes the historical scholarship on religion from European colonization to the Civil War seem pallid and offers powerful testimony to both the changes that transformed America after 1900 and the expansion of new approaches to writing modern American religion.

Sampling just two of the essays turns up astonishing, creative histories—religion and labor union members (not just leaders), religion among depression-era field workers in California’s San Joaquin Valley made famous in John Steinbeck’s Grapes of Wrath (1939), conservative Protestantism and American corporations, especially Walmart, religion in the Cuban diaspora, religion in social service agencies, reptiles and animals in humans’ religious worlds, religion and the environment, religion and oil, a not-always-secular secularism, religion and weather, links between Native American religion, dispossession, and nature, and a book on sheep, spirituality, and the Navaho (Diné), and more.

The remaining six essays deepen the range of post-2004 subjects. They focus on religion and the southern border crisis, religion in the American South, religion and punishment, religion in urban and suburban America, religion and American foreign policy, and religion in African American communities.

Are there still gaps in the historical accounts of religion in modern America? Probably yes. Are they as severe as they were twenty years ago? Probably not. Will authors of American history textbooks and broad accounts of modern America written for general non-academic readers now treat religion as a steady presence in modern America? These abundant histories will make it difficult not to. Still, it’s important to remember the fleeting character of historical interpretative modes. Perry Miller’s earliest books, Orthodoxy in Massachusetts, 1630-1650 (1933), and The New England Mind: The Seventeenth Century (1939), seemed to establish Puritan/Calvinist theological modes as the founding centerpiece of American culture. But in the early 1960s, a new group of historians studied New England towns that belied Puritan theological homogeneity. Then historians of religion in the middle and southern colonies challenged the Puritan claim for primacy in American religion, and powerful new slave histories made one wonder if, compared to enslavement and its brutalities, New England and Puritanism might actually be minor players in molding American culture and religion.

Some contemporary developments raise questions about religion’s continuing strength as the twenty-first century moves along. Substantial membership declines in almost all old-line Protestant denominations since 2000 and receding mass attendance among Catholics may signal a new phenomenon in American religion, the rise of the “nones” among younger Americans. Intriguingly, however, few “nones” have become atheists. Many imbibe a personal spirituality, vaguely defined, but eschew traditional religious institutions. They are “spiritual but not religious.”

On the other hand, our very recent politics demonstrates the power that religion can exercise in American life. First, disciplined evangelical voters played a critical role in Donald Trump’s victories in every “swing state,” guaranteeing his election and shaping Trump administration policies. Second, stressing the First Amendment’s “free exercise” clause, recent decisions of a more conservative U.S. Supreme Court have exempted religious groups and individuals from anti-discrimination laws and made religious groups eligible for public funds previously denied to them; the possibility of taxpayer-funded religious schools clearly seems on the horizon.

Can the abundant histories of American religion published since 2004 suggest anything about the next two decades of historical scholarship on religion? Surely that they will bring us chewy, fascinating stories. Issues that seem dominant today may or may not emerge as significant. New and familiar colleagues will probe previously bypassed subjects using fresh methods on long ignored sources.