John Brown’s raid on Harpers Ferry, Virginia (now West Virginia), in October 1859 was a futile effort by the white abolitionist John Brown to end the evils of slavery in the United States. John Brown’s raid on Harpers Ferry was a key incident in the march toward civil war, which would erupt just a year and a half later.

Historians have characterized the 1850s as a “decade of crisis.” The decade began with the Fugitive Slave Act of 1850, which said that anyone who helped a fugitive slave would be prosecuted and ordered northerners to aid in the capture and return of fugitive slaves. Fanning the flames of hostility between North and South was the publication of Harriet Beecher Stowe’s antislavery novel, Uncle Tom’s Cabin, in 1852, which had the effect of encouraging northerners to flout the Fugitive Slave Act—and to stiffen resistance in the South. Then, in 1854, the Kansas-Nebraska Act allowed the residents of the two territories to decide for themselves at the...