How did John Brown widen the divide between free and slave states?

Harpers Ferry, Virginia, lay sleeping on the night of October 16, 1859, as 19 heavily armed men stole down mist-shrouded bluffs along the Potomac River where it joins the Shenandoah. Their leader was a rail-thin 59-year-old man with a shock of graying hair and penetrating steel-gray eyes. His name was John Brown. Some of those who strode across a covered railway bridge from Maryland into Virginia were callow farm boys; others were seasoned veterans of the guerrilla war in disputed Kansas. Among them were Brown's youngest sons, Watson and Oliver; a fugitive slave from Charleston, South Carolina; an African-American student at Oberlin College; a pair of Quaker brothers from Iowa who had abandoned their pacifist beliefs to follow Brown; a former slave from Virginia; and men from Connecticut, New York, Pennsylvania and Indiana. They had come to Harpers Ferry to make war on slavery.Region that had 90 percent of the nation's industry