In early 2018, Matthew Pearl told his longtime agent, WME’s Suzanne Gluck, his idea for a nonfiction book. When he said “Daniel Boone,” she admits, “my heart did not flutter.” They laugh about it now, because once she saw the proposal she didn’t have any doubts that he would be writing an important page-turner of a book. The Taking of Jemima Boone: Colonial Settlers, Tribal Nations, and the Kidnap That Shaped a Nation, about the kidnapping of Daniel Boone’s 13-year-old daughter by a Cherokee-Shawnee raiding party in July 1776, will be published in October by Harper.

Jemima—along with two other girls from Boonesboro, the Kentucky settlement founded by Boone—was captured while canoeing on the Kentucky River, a little-known event that Pearl has spun out into the story of westward expansion. The Declaration of Independence had been signed only weeks before. Kentucky was contested territory, and when Hanging Maw realized one of his captives was Boone’s daughter, he saw her as an asset in peaceful negotiations. But Boone and his compatriots ambushed the raiding party, and the violence that is part of American history inevitably escalated.

A master of literary historical thrillers, Pearl has written six novels, beginning in 2003 with his bestselling The Dante Club, completed when he was at Yale Law School. He wrote it quietly, telling no one, and sent it to Gluck.

“He tracked me down from the acknowledgements page of Caleb Carr’s The Alienist,” Gluck tells me. “His passion was Dante, and he’d done this deep dive, and I remember the last line of his letter: ‘Please don’t make me be a lawyer!’ ” She hesitates with this last-line story, afraid that it might find its way into every future query letter to every agent. But I can’t resist repeating it. (Pearl graduated but never took the bar.)

“Each of Matthew’s novels is deeply informed by history,” Gluck says. “When we talked about a nonfiction book, I suggested he read two of my writers, Candice Millard and Simon Winchester, to understand how a small moment can be a window into a big story.”

Gluck calls the result “the multilayered story of a dramatic kidnapping,” adding, “Matthew humanizes all the players: the tribes, the settlers, and the third piece of the triangle, the British, who were working to advance their own agenda.” Pearl is sensitive to the complicated politics of the times, and, Gluck notes, “there’s so much about Daniel Boone the legend, but Matthew’s gotten to the real man, and he’s given the women their due. We know of Boone but not Jemima, a young girl who was so smart, a survivor, a strategist.”

Describing the kidnapping, Pearl writes, “Jemima proved herself her parents’ daughter, suppressing fear and anger, concentrating on assessing the scene and their situation.” And, “After walking with their captors for a short time, Jemima stopped and refused to budge. ‘I would rather die,’ she announced.... She showed her wounded foot.... One of the Indians threatened Jemima. She didn’t scream, but still refused to move.”

Pearl first realized he wanted to write more nonfiction when he was doing long-form pieces. “I really enjoyed writing the articles, and I really like research,” he says. “I was utilizing the skill set I’d developed on the fiction side and exercising some different muscles.”

Teaching a seminar at Harvard Law School on literary copyright in the 19th century, Pearl chose a different writer each week. “I came across James Fenimore Cooper and started reading,” he says. “It got me thinking about where The Last of the Mohicans came from.” He adds that Cooper “was the entry point” to Jemima Boone. “I came to the rule that if a story doesn’t need to be fictionalized, if it has all the elements planted in the actual events to make the story, then stick with nonfiction.”

Pearl started writing The Taking of Jemima Boone in earnest three years ago. He discussed the idea with Gluck and the proposal went out to publishers in September 2018. “We had lots of choices,” Gluck says. “Matthew is a unique brand, he’s inspired by literature and history, and this is a tight, exciting read. He can write a wildly original novel and brought this talent to nonfiction. Matthew has the sense of the reader in the chair and keeping him there. This book is magic. You can’t stop reading.”

There was an auction, and Sara Nelson, executive editor at Harper, won it. “She was the right fit, and HarperCollins was the right place,” Gluck says.

“I knew nothing about Jemima Boone when I got the proposal,” Nelson recalls. “I liked the idea of history through the story of a less well-known source—to see early America through the experiences of this young woman. I love this book because it doesn’t feel like history homework. It’s exciting, dramatic, cinematic. Matthew and I had a great conversation, and there wasn’t much to change editorially.” She bought North American rights in October 2018 for, she says, “a solid six figures.”

Pearl notes that nonfiction is a leap of faith. “It’s based on a proposal, so it’s an uphill battle; there’s no book.” He met with eight editors, he says, but “clicked” with Nelson. “We met one-on-one and I felt we could just keep talking. Sara completely got the material and what I was excited about.”

“Matthew was so young when I signed him,” Gluck says. “A literary prodigy. We’ve been together through all six novels. I watched him grow up!”

For his part, Pearl says, “If she retires to Hawaii, what will I do?”

Correction: An earlier version of this article misidentified Candice Millard.