Finding topics to write about has never been a problem for Jill Lepore. The Harvard historian’s fascination with everything from Wonder Woman and Frankenstein to matters of life and death has fueled her New Yorker essays and nonfiction for years. But when your project is a single volume covering a nation’s centuries-long past, not every fascinating topic is going to make the cut. The Bancroft Prize winner and David Woods Kemper ’41 Professor of American History said that adhering to a strict timeline and specific themes helped her narrow her subject matter for the just-published “These Truths: A History of the United States.” Still, she admitted, the selection process often kept her up late.

Lepore spoke with the Gazette about our shared past, her central argument, Supreme Court fan mail, and more.

GAZETTE: With this kind of sweeping project, how did you decide what to leave out?

LEPORE: There’s a lot of lying in bed at night making a list of all the things you’ve left out and worrying about them. It’s hard to make your peace with that. How it works in the book is it’s a relentlessly chronologically organized narrative. And yet within that, each chapter has a theme, so that means I have a clothesline with clothespins. The clothesline is the timeline and then I have the pins, which are my themes, so there are only certain clothes that I can hang up.

For example, in the last chapter, which is called “America, Disrupted” and runs from 9/11 to the election in 2016, the clothesline is just those years and then I cover the attack on 9/11, the Obama election, the war on terror, the Trump election. But thematically the chapter is really about how the internet, and social media in particular, transform American political arrangements. So I had to select things that hit on those themes. I talked about Black Lives Matter, but more from the vantage of how interesting it is to be able to capture police brutality live and make it visible to the entire world as it’s happening through Periscope and less about how we understand the relationship between Black Lives Matter and the Black Power movement, which is another very important discussion.

The decisions were about what theme would make this stretch of years most legible to a reader. Then I had to stick on that theme so the reader can walk away from that chapter feeling as though she learned something and that the knowledge has been organized in a way that she can absorb it and also dispute it. It’s not meant to be a stone tablet. The whole argument of the book is that the study of history is an inquiry. ...