The Battle of Wilson's Creek was also known as the Battle of Oak Hills. It was fought between the Union forces and the Missouri State Guard. It was the first major battle west of the Mississippi River and is sometimes called the "Bull Run of the West."
When war broke out in 1861, President Abraham Lincoln called for troops from the states to support the Union's cause. Missouri was asked to send 4 regiments, but Governor Claiborne F. Jackson was a Confederate sympathizer and refused the request. Instead, Jackson summoned the Missouri State Guard to seize the St. Louis Arsenal. His plan was stopped by the newly appointed commander of the arsenal and the 2nd U.S. Infantry, Capt. Nathaniel Lyon. He was politically connected to Postmaster General Montgomery Blair. Blair arranged for his promotion to brigadier general and saw that he was given command of the Army of the West from Gen. William S. Harney, a moderate.
Respecting the neutrality of Kentucky, the Confederates undertook to gain control of Missouri. In the beginning of August, there was a Confederate force of about 10,000 militia and volunteers from Missouri, Arkansas, and Louisiana advancing from southwest Missouri. At Pocahontas, in northeast Arkansas, Brig. Gen. William J. Hardee was organizing 5,000 Arkansas volunteers. M. Jeff Thompson's "Mushrats" were nearby in southeast Missouri. At New Madrid, on the Mississippi River, a force of 6,000 Tennessee troops under Brig. Gen. Gideon Pillow was located. The separate commands were expected to cooperate in an advance on St. Louis.
Lyon had assumed control of military affairs in Missouri. Col. Franz Sigel had clashed with Jackson's forces at Carthage on July 5, and then withdrawn to join Lyon at Springfield. Since his department commander, Brig. Gen. John C. Fremont, showed no concern for the safety of his force and would give him no support, Lyon had determined to take the offensive against the advancing Confederates.
By the end of July, the Missouri State Guard was camped about 75 miles southwest of Springfield and had been reinforced by Brig. Gen. Benjamin McCulloch and Brig. Gen. N. Bart Pearce. They formed plans to attack Springfield, but Lyon marched out of the city on August 1 in an attempt to surprise the Confederate forces. The armies' vanguards skirmished at Dug Springs on August 2. The Union vanguard emerged as the victors, but Lyon learned he was outnumbered more than 2-to-1 and retreated back to Springfield. McCulloch, now in command of the Missourian army, gave chase.
On August 6, the Missourian army was encamped at Wilson's Creek, 10 miles southwest of the city. Outnumbered, Lyon planned to withdraw to Rolla in the north to reinforce and resupply, but not before launching a surprise attack on the Missourian camp to delay pursuit. Col. Franz Sigel, Lyon's second-in-command, developed an aggressive strategy to split the Union force. He proposed to lead 1,200 men in a flanking maneuver while the main body under Lyon struck from the north. Lyon approved the plan.
On August 9, the Union army marched out of Springfield on a rainy night, leaving about 1,000 men to protect supplies and cover the retreat. The success of the strategem was dependent on the element of surprise. Ironically enough, McCulloch was also planning a surprise attack on the city but the rain caused him to cancel his plan.
Lyon’s Army of the West was camped at Springfield, with Confederate troops under the commands of Brig. Gen. Ben McCulloch approaching. Both sides formulated plans to attack the other, McCulloch confident in superior numbers and Lyon as a pre-emptive attack. Lyon left about 1,000 men behind to guard his supplies, the Union commander led 5,400 soldiers out of Springfield that night. Lyon's plan called for 1,200 men under Sigel to swing wide to the south, flanking the Confederate right, while the main body of troops struck from the north. Success hinged on the element of surprise.
On August 10, at about 5:00 A.M., Lyon's attack caught the Confederate army off guard, driving them back. Forging rapidly ahead, the Federals overran several Confederate camps and occupied the crest of a ridge subsequently called "Bloody Hill." Confederate cavalry received the first blow and fell back away from Bloody Hill. Nearby, the Pulaski Arkansas Battery opened fire, checking the advance and allowing their infantry time to form a new battle line on the hill's south slope. The Confederates attacked the Union forces 3 times that day, over 5 hours but failed to break through the Union line.
On Bloody Hill at 9:30 A.M., Lyon, already twice wounded, was killed leading a countercharge and Maj. Samuel D. Sturgis replaced him. Meanwhile, after initial Union success, the Confederates had routed Sigel’s column south of Skegg’s Branch. Sigel’s defeated men fled.
Following the third Confederate attack, which ended at 11:00 A.M., the Confederates paused. Sturgis realized, however, that his men were exhausted and his ammunition was low, so he ordered a retreat to Springfield. The Confederates were too disorganized and ill-equipped to pursue.
This Confederate victory buoyed Confederate sympathizers in Missouri and served as a springboard for a bold thrust north that carried Price and his Missouri State Guard as far as Lexington. Though the Missourians won the field, as Lyon had hoped they were unable to pursue the retreating Union army to Rolla. The Missourian army eventually moved north through Missouri, but lacked the strength to take the cities necessary for political leverage. Missouri remained under Union control.