Back that up!
On the night of May 24, 1856, John Brown and his company of Free State volunteers murdered five men settled along the Pottawatomie Creek in southeastern Kansas. The victims were prominently associated with the pro-slavery Law and Order Party, but were not themselves slave owners. This assault occurred three days after Border Ruffians from Missouri burned and pillaged the anti-slavery haven of Lawrence, and two days after Massachusetts Senator Charles Sumner was severely beaten by Senator Preston Brooks of South Carolina.At the Doyle farm, James and two of his sons, William and Drury, were dragged outside and hacked up with short, heavy sabres donated to Brown in Akron, Ohio.
http://xroads.virginia.edu/~HYPER/CONTEXTS/Kansas/jbrown.html
1858 [Lysander Spooner] Writes "A Plan for The Abolition of Slavery (and) To The Non-Slaveholders of the South," a plan to abolish slavery through the use of guerilla forces from both the North and the South. It is not carried out because John Brown fears it would alert the South to his plan of attack.
http://members.aol.com/Dreom/spbio.html
John Brown was certainly familiar with Spooner’s work. Gerrit Smith, Spooner’s benefactor, had been very close to Brown, supplying funds for his stays in Kansas and for the Harper’s Ferry raid. Smith made a point of sending his friends copies of Spooner’s Unconstitutionality of Slavery. John Brown and Spooner met in Boston shortly before Harper’s Ferry. And although he was told little about the details of the raid beforehand, Spooner had confidence in its success and, after the raid, admired Brown as a model of just action.
http://www.lysanderspooner.org/BIOch5.htm
When John Brown failed and was imprisoned, Lysander Spooner made another proposal for a guerilla action. He suggested the capture of Governor Henry Wise of Virginia, who could be held hostage for Brown’s release. Spooner planned an attack by sea through the Chesapeake Bay and James River; this area was already a haven for runaway slaves, smugglers, and others outside the law. A group could reach Richmond, the state capital, and kidnap the governor on his evening walk; once out to sea, they would be relatively safe. John LeBarnes wrote Thomas Wentworth Higginson, November 15, 1859, "LS [Lysander Spooner] called upon me yesterday. His idea has certainly the merit of audacity."
http://www.lysanderspooner.org/BIOch5.htm