In September of 1861, just weeks after Bull Run, armed conflict broke out in Lexington, Missouri. Opposing forces had begun jockeying for position in the West even before the first Battle of Manassas. In Kansas and Missouri, abolitionists struggled with pro-slavery forces for control of the states. Bloody battles broke out all over the place. Forward thinking military leaders on both sides, realizing the importance of the northern Mississippi River, began campaigns to control the ports and the Western Territories