Most high school history books will tell you the War Between the States began with the attack on Fort Sumter in South Carolina. However, the Civil War's actual start can be traced back to the Border Wars between Missouri and Kansas. In fact, Midwest skirmishes between pro-slavery and anti-slavery factions date back to the 1850s.
These polarizing ideologies became nationwide hot buttons as more and more states applied for entry into the Union. This led to some of the fiercest fighting long before any actual declaration of war. When the Civil War began in earnest, Missouri supplied troops to both the Union and Confederate Armies. Bloody battles and skirmishes to place across the state, including the First and Second Battles of Independence. Relics of these Civil War Sites can still be seen today.