John Brown (May 9, 1800-December 2, 1859) was a Congregationalist abolitionist whose violent actions to hurt slavery helped start the American Civil War. His raid on Harper's Ferry Virginia in 1859 was designed to start a slave insurrection, but no slaves joined and it failed. Brown was tried and hung for treason to the state of Virginia.
Unlike most abolitionists, Brown believed that the use of violence was morally justifiable in the fight against slavery. He was born into a religious Yankee family, and was taught from a young age that slavery was incompatible with the message of the Bible. 
Brown became a part of the Underground Railroad, then went to the newly formed territory of Kansas in 1855 to participate in the fight between the "free staters" and the pro-slavery "Bushwhackers". In May 1856, Brown and several other men (including four of his sons) attacked the homes of slavery supporters near Pottawatomie Creek in Kansas and killed all of the inhabitants with swords.
Harper's Ferry 1859
Brown now made even more gradiose plans and signed up famous men in Boston who gave him the necessary money. They included Gerrit Smith, George L. Stearns, Theodore Parker, Frank B. Sanborn, Thomas Wentworth Higginson, S. G. Howe, Frederick Douglass, and others.
His plan was not a sudden raid and then escape to the mountains. Rather his plan was to use the rifles and pikes he brought along, and those captured at the arsenal, to arm rebellious slaves, striking terror to the slaveholders in Virginia. He believed that on the first night of the stroke he thought he might get from two to five hundred black adherents. He ridiculed the militia and regular army that might oppose him. Then he would send agents to nearby plantations, rallying the slaves. He planned to hold Harper’s Ferry for a short time, expecting as many volunteers white and black would join him as would form against him. He then would make a rapid movement southward, along the way sending out armed bands. They would free more slaves, obtain food, horses and hostages, and destroy slaveholding morale. Brown planned to follow the Appalachian mountains south into Tennessee and even Alabama, the heart of the South, making forays into the plains on either side.
In 1859, Brown led 21 men in an attack on a federal arsenal in Harper's Ferry, Virginia (note: Harper's Ferry is now part of West Virginia), intending to arm slaves in slave revolts. The raid failed, and Brown was hanged on December 2.
"Bleeding Kansas" of 1851-64 has been a major topic of historical research and debate. In the first wave of 19th-century historiography, scholars included Kansas under the broader rubric of the "irrepressible" national conflict over slavery. Revisionist scholars in the early 20th century, led by Kansas historian James C. Malin, a conservative, denied the need for conflict, suggested that Kansas would have become a free state even without the effort of New England antislavery settlers, and debunked the legend of John Brown. New scholarship in the 1950s on the power dynamics of land settlement further displaced the issues of slavery and sectional conflict from the center of understanding of Bleeding Kansas.
In the 1970s-1980s, a new social and cultural history led by Neoabolitionist historians reappraised the antislavery movement - recognizing its complexity, its centrality to the creation of Kansas as a free state, and its moral concerns. Later historians have again shifted their interpretation away from issues of the Civil War toward the experience of frontier and questions of how gender and racial identities were enacted and negotiated in the process of settling Kansas.
- Etcheson, Nicole. "John Brown, Terrorist?" American Nineteenth Century History, Volume 10, Issue 1 March 2009 , pp 29-48, answers "no"
- Etcheson, Nicole. Bleeding Kansas: Contested Liberty in the Civil War Era (2006) excerpt and text search
- Nevins, Allan. The Emergence of Lincoln: Prelude to Civil War, 1859-1861 (1950), vol 4 of The Ordeal of the Union, outstanding narrative, esp ch 3 pp 70-97
- Peterson, Merrill D. John Brown: The Legend Revisited. (2002). 196 pp.
- Potter, David M. The Impending Crisis: 1848-1861 (1976) pp 211-24, 356-84; Pulitzer Prize winning history by leading conservative historian
- Reynolds, David S. John Brown, Abolitionist: The Man Who Killed Slavery, Sparked the Civil War, and Seeded Civil Rights (2006) says Brown was justified in practicing terrorism
- Villard, Oswald Garrison. John Brown, 1800-1859: A Biography Fifty Years After (1910) 738 pages, a better balanced biography by an abolitionist full text online