Sensationalized history can be credited with inspiring generations of truth-seeking experts and enthusiasts. The tragedy of the Johnstown Flood was an oft-exploited event as writers and publishers hawked hastily written articles in original form or pirated collections. Where many of the articles lacked fact, they were rife with exaggeration and imagination.

James Herbert Walker published one of the very first of these books, The Johnstown Horror, a pamphlet of some 40 pages. Experts cite the book as being sold in New York within a week of the disaster. Though the structure...