Missouri was the 24th state admitted to the United States. It was admitted as a slave-state, which proved pivotal in the country's later history. When the South seceded, Missouri did not vote to secede with it. The loyalties of the people were split, and military conflict in the state prevented it from successfully joining the Confederate States. Slavery was legal in Missouri until the 13th Amendment was ratified on December 6, 1865.
Missouri was one of the states the newly-independent Confederacy sought to annex after the Second American Revolution, along with Kentucky. The U.S. and the C.S. agreed to a plebiscite in each state. During the plebiscite, Missouri voted to remain with the United States while Kentucky voted to join the Confederacy.
Throughout its history, the population of Missouri was divided in its loyalties, with a sizable portion of the state having pro-Confederate sympathies. Rioting, sabotage, bushwhacking and minor revolts broke out during the War of Secession, the Second Mexican War, and both Great Wars. By the Second Great War, Missouri still had some stubborn Confederate sympathizers. C.S raiders would also frequently sneak up into Missouri from Arkansas.
The borders of this province are considerably different from that of OTL state. This Missouri contains Missouri south of the Missouri River, northern Arkansas, all of Kansas, and Nebraska south of the Platte River. The rest of OTL Missouri is part of the province of Mississippi.