Following the morale-sapping Union defeat at Wilson's Creek and with Confederate General Sterling Price both occupying Lexington, Missouri and expecting reinforcement, Frémont's Army of the West started to move in steamers from S. Louis up the Missouri River against the invasion. The numbered around 20,000 men, including 5000 cavalry, and was organized in five divisions, under Generals David Hunter, John Pope, Franz Sigel, J.A. McKinstry, and Alexander Asboth. (By John Osborne)