For some, John Brown (1800-1859), the armed and incendiary abolitionist, was a hero. For others, he was a murderer, certainly an insurrectionary. Dyer was fascinated when she learned that he once lived in her small Ohio town—and possibly spent time in her own house—and she borrows biographer Richard Holmes’ “footsteps principle” to follow her subject of inquiry from place to place. “Returning to the physical places a person once occupied always seems such a private and mysterious act,” she writes, “a way of finding something out that reading alone can’t supply.” Though her reading of Brown’s history is extensive, the book benefits from the author’s hands-on approach to the principal places of his life and death, including apex moments such as Brown’s massacre of pro-slavery settlers in Kansas and his capture (by a rising young officer named Robert E. Lee) at the federal arsenal in Harpers Ferry, from which he intended to spark an uprising of enslaved Black people. Along the way, Dyer explodes a few myths and realigns others: For one thing, the Underground Railroad seldom involved the cellars and tunnels of legend, and its stations were inhabited more by freed Black people than by well-meaning Whites. On that score, the author takes a hard look at her hometown to find that only about a third of its pre–Civil War inhabitants were ardent abolitionists, about as many as those who believed the South should remain a slave-based economy. These two observations coincide: “Compared with the number of abolitionists who lived in Hudson,” she writes, “there really were few residents known to have engaged in Railroad activity.” Even the remembrance of Brown, largely forgotten in textbooks, was largely the project of Black people decades after his hanging. Dyer ranks alongside the late Tony Horwitz in her explorations of the past.