The book was supposed to end with the inauguration of Barack Obama. That was Jill Lepore’s plan when she began work in 2015 on her new history of America, These Truths (W.W. Norton). She had arrived at the Civil War when Donald J. Trump was elected. Not to alter the ending, she has said, would have felt like "a dereliction of duty as a historian."

These Truths clocks in at 789 pages (nearly 1,000 if you include the notes and index). It begins with Christopher Columbus and concludes with you-know-who. But the book isn’t a compendium; it’s an argument. The American Revolution, Lepore shows, was also an epistemological revolution. The country was built on truths that are self-evident and empirical, not sacred and God-given. "Let facts be submitted to a candid world," Thomas Jefferson wrote in the Declaration of Independence. Now, it seems, our faith in facts has been shaken. These Truths traces how we got here.

Lepore occupies a rarefied perch in American letters. She is a professor at Harvard University and a staff writer at The New Yorker. She has written books about King Philip’s War, Wonder Woman, and Jane Franklin, sister of Benjamin Franklin. She even co-wrote an entire novel in mock 18th-century prose. The Princeton historian Sean Wilentz has said of Lepore: "More successfully than any other American historian of her generation, she has gained a wide general readership without compromising her academic standing."

Lepore spoke with The Chronicle Review about how the American founding inaugurated a new way of thinking, the history of identity politics, and whether she's tired of people asking about her productivity.

Q. These Truths is a civics book, which used to be more common. Then they became kind of untenable, and even looked down on by academic historians.

A. This kind of book written by a single author for a general readership is an unusual effort. It hasn’t been done often, though it used to be a routine capstone endeavor of a certain sort of notable historian. It became untenable when the historical profession became bigger and broader. In the 1960s, women and people of color got Ph.D.s and revolutionized the study of the past. They incorporated those whose experiences and especially whose politics had been left out. You can think of that, and I certainly do, as an incredible explosion of historical research that was profoundly important and urgently necessary. But you can also think of it as shattering an older story of America.

Post-1968 or so, the kind of book you get is Howard Zinn’s A People’s History of the United States. Zinn was a political scientist. The book was an outgrowth of his work in the antiwar movement. It’s a Marxist reckoning with American atrocity. On the other side of the political spectrum, there emerged the American triumphalism of popular history. It’s in this era that academics retreat and what the public reads is presidential history written chiefly by journalists — the McCullough/Meacham tradition of the journalist who writes about men and power. ...