Missouri was a slave state, but never an actual member of the Confederacy. Two factions claimed to represent Missouri’s legitimate government, but only the Unionist one retained control of it. With war looming in 1860, Governor Robert Marcellus Stewart adopted a policy of “armed neutrality” – Missouri would stay in the Union, but send aid to neither side, and resist any attempts at invasion. Governor Claiborne Fox Jackson, who took office in January 1861, reaffirmed that policy – but as it turns out, Jackson had Southern leanings and, despite a constitutional convention that voted overwhelmingly to stay in the Union, started plotting to seize the federal arsenal at St. Louis as a prelude to secession. But troops guarding the arsenal, under the command of Captain Nathaniel Lyon, ambushed the Missouri Volunteer Militia as it was maneuvering at Camp Jackson near St. Louis. Lyon’s troops paraded the captured militiamen through St. Louis, to the disapproval of the locals; at one point a shot rang out, prompting a response from Lyon’s troops that left 28 people dead. The next day the Missouri General Assembly authorized the creation of the Missouri State Guard allegedly to resist invasion, but in reality to keep Federal troops locked up in St. Louis; after about a month Lyon, now commander of the Department of the West, ended up chasing Jackson and his legislative supporters out of the state capital at Jefferson City. They reassembled in Neosho, Missouri and enacted an Ordinance of Secession in late October, and a month later the state was admitted to the Confederate States of America. But all this was notional: Jackson’s government may have been legitimate on one level, but back in Jefferson City the reconvened constitutional convention declared that the governorship was vacant, and appointed Hamilton Rowan Gamble, a former Missouri Supreme Court Justice, to the position. Hamilton’s government retained hold of the machinery of state, and began recruiting troops for the Union. Ultimately some 447 regiments fought for it. For its part, Jackson’s government eventually retreated to Marshall, Texas, where it did not do much but did send representatives to the Confederate capital of Richmond, Virginia.
But that didn’t mean that pro-Confederates went away gently. Few formal Civil War battles were fought in Missouri. Instead, the state’s Civil War experience was largely characterized by guerrilla warfare, of a savage and brutal nature. Pro-slavery “Bushwackers” (including William C. Quantrill, “Bloody Bill” Anderson, and a young Jesse James) attacked anyone suspected of sympathizing with the Union cause; in return, Kansas-based anti-slavery “Jayhawkers” did the same thing. In some ways this was a continuation of “Bleeding Kansas” of the 1850s – and such activity continued after the war’s formal conclusion in 1865. It’s really quite amazing how horrible it all was.
All of this and more is well presented at the Missouri Civil War Museum at Jefferson Barracks in St. Louis, Missouri, which I highly recommend. It was funded entirely by local fundraising and has a great bookstore to boot.