The Western Theater and Price's Raid

The Civil War's Western Theater experienced several forays by Confederates into sparsely-populated territories of the Union-held American West. One such region was the Kansas-Missouri border. Missouri was officially Union but was a slave state that contained significant numbers of Southern sympathizers. Some residents raided neighboring Kansas. Missouri was the base for , who had launched his infamous in 1863.

Southern military leaders also acknowledged this strong element of Southern sympathizers in Missouri. In 1864, Major General , commander of the South's Trans-Mississippi Department met with Major General , commander of the District of Arkansas to plan an invasion of Missouri. The hope was that such actions would be enough to rally pro-Southern elements in that state. Even if that part did not succeed, the raid would hopefully disrupt the 1864 presidential elections and obtain needed animals, supplies, and soldiers for the Confederate cause. A Missourian himself, would lead the raid. Should fail to take Missouri, he was to retreat along the Kansas-Missouri border, striking a glancing blow to the symbol of Free-soil sentiments in the region: Kansas.

In September of 1864, 's Army of the Missouri set out with 12,000 cavalry troops and supporting artillery. The Army was organized into three divisions, commanded by Generals (like a Missourian), , and . division consisted of troops from Arkansas organized into four brigades. and had divisions with two brigades each that consisted mostly of pro-Southern Missourians. Each brigade consisted of a number of state-based regiments, the primary unit during the Civil War.

The speed, mobility, and power of mounted units made cavalry a valuable tool in a number of situations. Cavalry units were useful in pursuing a fleeing enemy. Mounted troops were utilized in anti-guerrilla campaigns, such as those of Ewing's Order Number 11 policy. During the Civil War military leaders on both sides also used cavalry to outflank and surprise enemy positions as well as for scouting and reconnaissance patrols. In addition, cavalry troops were effective in conducting quick raids on specific targets. 's forces were mostly cavalry units, suggesting a need for a lightning fast action. These units were designed to capture and surround, not invade or lay siege. and wagered that there would not be enough resistance among the locals to require large numbers of infantry.

crossed into Missouri near Doniphan on September 19. He moved towards St. Louis, hoping to take the city. However a defeat at Pilot Knob on September 27 allowed Union forces enough time to group and secure the city's position. redirected his forces to take the Missouri capital of Jefferson City. By the time reached the outskirts of Jefferson City, he found that Federal troops were well entrenched there as well. Turning to the northwest again, headed toward Kansas City capturing supplies and rallying some soldiers along the way. By now, oversaw more than a group of cavalry units. There was an immense baggage train filled with supplies and arms headed for the Confederacy. In pursuit were 7,000 Union Cavalry from the Department of Missouri under the command of General . had commanded cavalry forces for the Army of the Potomac and had engaged General at Brandy Station, the largest cavalry engagement of the war. By 1864, however, had fallen out of favor with the leaders back east and was transferred to the Department of Missouri just in time to face raid.

Meanwhile, Major General , commander of the Department of Kansas, started to rally his forces to meet . At the time, the Department of Kansas covered a vast territory from Nebraska in the north to Colorado in the west and Indian Territory to the south. The Department contained 4,000 troops, many of whom were engaged in pacifying the Cheyenne and Arapaho. hastily formed the "Army of the Border" consisting of cavalry units from Colorado, Kansas, and Wisconsin. also mobilized the 10,000 troops of the Kansas State Militia into the effort as well as units of African American troops. organized his forces into two divisions, one consisting of the state units under General . The other division, under Major General , oversaw the militia. Even so, was not sure he would be able to defend Kansas from . He had reason to be worried. By late October, was advancing fast on Kansas City. forced back forces at the battles of the Little Blue, Independence, and the Big Blue.

A turning point took place on October 23. directed General division to attack outside of Kansas City. At this engagement, now called the Battle of Westport, the Kansas Militia checked advance. Meanwhile, forces were catching up to army. Failing to capture a third major city or penetrate deep into Kansas, retreated along the Kansas Missouri border. By now, nearly 9,000 Union men were in pursuit. Northern and Southern forces tried to outflank each other along the border. Each time, escaped but left in his wake a trail of burned homes and looted farms. Union troops hurriedly raced to reinforce Mound City, next objective. When received news of the city's defense, he decided to avoid that community and instead continue down the Old Military Road towards Fort Scott.