Through his family connections with Dr. Sappington, Jackson, along with his brother-in-law
Meredith M. Marmaduke, became deeply involved with Missouri
Democratic Party politics. Jackson was first elected in 1836 to the
Missouri House of Representatives, where he represented Saline County. He moved to the Howard County seat of
Fayette, Missouri—then a center of political power in the state—in 1838 and worked for the local branch of the state bank. This would pay great political dividends later in his career. Asserting that Congress had no constitutional right to legislate on slavery in the states, the resolutions rejected the
Missouri Compromise and any effort by outside forces to determine slavery in a territory, but said to preserve harmony it would accept extension of the Compromise to all new territories. It stated that Missouri had much in common with other slaveholding states and needed to resist Northern encroachment. It mandated that the state's U.S. Senators and Congressmen support these resolutions. As Commissioner, Jackson traveled to various locations around the state inspecting banking facilities. He used these occasions to build a power base for his next attempt at elected office, as a candidate for Governor of Missouri. Jackson assumed the governor's office on January 3, 1861. During his inaugural address, he declared that Missouri shared a common bond and interest with other states that allowed slavery and could not separate herself from them if the Union should be dissolved. He called for a state convention to decide the issue. On February 18, Missourians voted to have a
special state convention to decide on secession and other matters. The convention delegates voted overwhelmingly 98–1 against secession, despite lobbying by Jackson. Jackson announced that he would continue the policy of his predecessor, Governor
Robert M. Stewart, whereby Missouri would be an "armed neutral." The state would refuse to provide arms or men to either side in the approaching Civil War. After the Confederate
bombardment of Fort Sumter in South Carolina on April 12–13, President
Abraham Lincoln issued a proclamation for the states to call up their militia and provide 75,000 troops to the Federal government to suppress the rebellion. He sent specific requests to all states, including Missouri. Jackson responded, In this period, Jackson was carrying on secret correspondence with Confederate President
Jefferson Davis, making plans to take Missouri out of the Union by a military coup. The key asset was the
U.S. Arsenal in St. Louis, which contained large stocks of arms and ammunition. Jackson plotted to seize the Arsenal, and asked Davis to send artillery to breach the Arsenal's walls. The commander of the Arsenal was
Captain Nathaniel Lyon, a pro-Union
regular Army officer. On April 26, 1861, under orders from Secretary of War
Simon Cameron, Lyon worked with Missouri Volunteers and Illinois troops to secretly move 21,000 weapons (of 39,000 small arms held in the Arsenal) across the
Mississippi River to
Alton, Illinois, in order to protect them.
Capture of Camp Jackson On May 3, 1861, Jackson ordered the
Missouri Volunteer Militia to assemble at various encampments throughout Missouri, including
St. Louis, for six days of training. They assembled in Lindell's Grove on the city's western outskirts, in an encampment now called Camp Jackson. Governor Jackson's order to assemble the militia was legal according to the
Missouri state constitution, if the encampment was intended only for training, and not for offensive action against Federal forces. But, the St. Louis Militia was commanded largely by secessionists, and had recently enlisted a new regiment (2nd Regiment MVM) composed almost completely of secessionists. Also, Confederates had shipped artillery seized from the U.S. Arsenal in
Baton Rouge. Arriving by steamboat, the artillery was secretly delivered to Camp Jackson. Lyon responded to the perceived threat to control of the Arsenal with force. On May 10, 1861, Lyon surrounded Camp Jackson with pro-Union volunteer "Home Guards" (mostly drawn from the German immigrants of St. Louis), and took the Militia prisoner. As the prisoners were marched to the Arsenal, a riot broke out on the streets. During two days of rioting and gunfire, several soldiers, prisoners, and civilian bystanders were killed. Alarmed by the incident, the Missouri Legislature immediately acted on Governor Jackson's call for a bill dividing the state into military districts and authorizing a
State Guard.
American Civil War On May 11, 1861, Jackson appointed
Sterling Price to be
Major General of the Missouri State Guard; he ordered him to resist action by federal forces and Missouri Unionist Volunteers in Federal service. On May 12, Price met with General
William S. Harney, the Federal commander in Missouri. They agreed to the
Price-Harney Truce, which permitted Missouri to remain neutral for the moment. Theoretically, Price promised that the state forces, and the state government, would hold the state for the Union and prevent the entry of Confederate forces. But, at the same time Governor Jackson had secretly dispatched envoys to CSA President Jefferson Davis and Confederate commanders in Arkansas asking for an immediate invasion of the state. He promised that the State Guard would cooperate with the Confederate Army in a campaign against Federal forces to effect the "liberation" of St. Louis. In addition, Lieutenant Governor
Thomas C. Reynolds traveled to Richmond, with the agreement of Major General Price, to ask President Davis to order an invasion of the state. Missouri Unionists were dismayed at what they perceived as Harney's one-sided adherence to the "truce," and petitioned for Harney's removal from command. Harney was removed on May 30, and temporarily replaced with Lyon. He was promoted from captain to brigadier general of
volunteers. On June 11, 1861, Jackson met with Lyon, hoping to extend the truce, but Lyon refused. Lyon marched on Jefferson City with his forces, entering on June 13. Jackson and other pro-Confederate officials fled to
Boonville, Missouri. Union forces routed the State Guard, commanded by Jackson's nephew
John Sappington Marmaduke, at
Boonville on June 17. At
Carthage on July 5, Jackson took command of 6,000 State Guardsmen (becoming the second sitting U.S. Governor to lead troops in battle after
Isaac Shelby of
Kentucky did so during the
War of 1812), and drove back a much smaller Union detachment led by Colonel
Franz Sigel. But, the Union forces held a dominating position, and Lyon chased Jackson and Price to the far southwest of the state. == Exile ==