Brown, born in Connecticut in 1800, first became militant during the mid-1850s, when as a leader of the Free State forces in Kansas he fought pro-slavery settlers in the sharply divided U.S. territory. Achieving only moderate success in his fight against slavery on the Kansas frontier, and committing atrocities in the process, Brown settled on a more ambitious plan in 1859.
With a group of racially mixed followers, Brown set out to Harpers Ferry in present-day West Virginia, intending to seize the Federal arsenal of weapons and retreat to the Appalachian Mountains of Maryland and Virginia, where they would establish an abolitionist republic of liberated slaves and abolitionist whites. Their republic hoped to form a guerrilla army to fight slaveholders and ignite slave insurrections, and its population would grow exponentially with the influx of liberated and fugitive slaves.
At Harpers Ferry on October 16, Brown's well-trained unit was initially successful, capturing key points in the town, but Brown's plans began to deteriorate after his raiders stopped a Baltimore-bound train and then allowed it to pass through. News of the raid spread quickly, and militia companies from Maryland and Virginia arrived the next day, killing or capturing several raiders. On October 18, U.S. Marines commanded by Colonel Robert E. Lee and Lieutenant J.E.B. Stuart, both of whom were destined to become famous Civil War generals, recaptured the arsenal, taking John Brown and several other raiders alive. On November 2, Brown was sentenced to death by hanging.
On the day of his execution, 16 months before the outbreak of the Civil War, John Brown prophetically wrote, "The crimes of this guilty land will never be purged away but with blood."