During the American Civil War, Missouri was a hotly contested southern border state populated by both Union and Confederate sympathizers. It sent armies, generals, and supplies to both sides, maintained dual governments, and endured a bloody neighbor-against-neighbor intrastate war within the larger national war.
A slave state since statehood in 1821, Missouri's geographic position in the central region of the country and at the rural edge of the American frontier ensured that it remained a divisive battleground for competing Northern and Southern ideologies in the years preceding the war. When the war began in 1861, it became clear that control of the Mississippi River and the burgeoning economic hub of St.