“Did John Brown fail? John Brown began the war that ended American slavery and made this a free Republic.” —Frederick Douglass

The late 1840s and the 1850s were a turbulent and complex time in American history as the country ground inexorably toward civil war. Abolitionist and pro-slavery positions hardened both north and south of the Mason-Dixon Line as events built toward a bloody confrontation. John Brown would be a catalyst that triggered the violent reaction. As he wrote just before his execution: “I...