In the aftermath of Abraham Lincoln's election, Jackson made it clear at his own inauguration that he strongly supported the southern states in their quarrel with the Union. While not calling for secession, Jackson advocated the convening of a state convention to resolve that issue. He also asked the legislature to provide for the reorganization of the militia to put the state on a war footing. The legislature agreed with the former proposal but stalled on the militia issue. When the convention met, it voted against secession, but Jackson still favored a prosouthern neutrality. When Lincoln called on him for volunteers after the firing on Fort Sumter, Jackson refused to furnish them, denouncing the request as "illegal, unconstitutional, and revolutionary." He secretly sought arms from the Confederacy while providing for militia encampments throughout the state, including one at St. Louis. The latter encampment, known as Camp Jackson, was surrounded by Union troops under General Nathaniel Lyon on 10 May  on the grounds that it was pro-Confederate and forced to surrender.
William E. Parrish, "Jackson, Claiborne Fox," American National Biography Online, February 2000, http://www.anb.org/articles/04/04-00551.html.