On October 16, 1859, John Brown and a group of 19 of his followers rode to Harpers Ferry.
Brown and his followers seized the federal armory and arsenal.
John Brown captured the Arsenal and killed four people to do it. Overnight he lost 10 men including 2 sons, and took people hostage. In the Morning they were surrounded and captured by the U.S. Marines.
Brown was then was tried by the state of Virginia for treason and murder and sentenced to death for the violence and blood he shed.
John Brown fought for a good cause being the end of slavery, but used violence instead of words. He murdered people for his cause and that is why he was executed.