In Flee North (Celadon, Sept.), journalist Shane spotlights Thomas Smallwood, a free Black man living in Washington, D.C., who led hundreds of enslaved people to freedom in the 1840s.

What was radical about Smallwood’s operation?
The hope was that, in addition to freeing those particular people, each escape would demoralize the slaveholders and undermine the enslaver system by making it uncertain and unprofitable. And the U.S. Capitol is right there. Some of the people he was helping to escape were actually escaping from members of Congress or the Cabinet. So it was sending a very direct message.

Which he amplified in letters to an abolitionist newspaper in Albany, N.Y. What was unique about them?
They constitute a very unusual kind of literary work, an unusual work of satire. And they’re unique in terms of being real-time accounts of escapes from slavery. The core aim of these dispatches is to mock the slaveholders, and to ennoble the people escaping slavery. It was really a turning of the tables. He would portray the slaveholders as a dim-witted bunch who were easy to outsmart.

Why did the dispatches cause such an uproar among Washington’s elite?
He’s taking advantage of his social invisibility and turning it into a kind of superpower. White people are having conversations around him in public and paying no attention to this shoemaker who’s there. And so he is able to hang out and take notes. He very much wants to send the message that “I am among you, I’m exposing your crimes. I’m exposing your use of violence against the people you enslave. I’m exposing you raping the women you enslave.” He writes about all that. He gets the paper to mail a copy of each issue to the slaveholders who are mentioned. He even describes, at one point, witnessing a slaveholder reading about himself in the paper, and losing it because he’s so furious at what’s happening to him.

Readers may be surprised to learn that the phrase “underground railroad” started as a joke.
Researching this book, I stumbled upon the solution to a 150-year-old mystery, which is where this term underground railroad comes from. Well, it turns out it comes from Thomas Smallwood. According to him, a notorious slavecatcher was overheard exclaiming in frustration that the escapees must be leaving by underground railroad or steam balloon.

At that point, those were futuristic, nonexistent modes of transportation. In other words, he’s just expressing his frustration. Smallwood got wind of this and starts riffing on it. A lot of these letters are framed as consolation to the bereaved slaveholders. So, he starts advising these enslavers to go to the Office of the Underground Railroad in Washington for further information about their lost loved ones. It becomes a running joke, and others pick up on it.