August 10, 1861
Fought on August 10, 1861, the Battle of Wilson's Creek was the first major Civil War battle fought west of the Mississippi River and the scene of the death of Nathaniel Lyon, the first Union general killed in combat.
When the American Civil War began, sympathies in the border state of Missouri were greatly divided. Although many Missourians favored remaining in the Union, Governor Claiborne Jackson was a strong proponent of secession. Despite his secessionist leanings, Jackson declared his support for the Union and affirmed Missouri's neutrality by agreeing to terms of the Price-Harney Truce on May 12, 1861. When President Abraham Lincoln requested 75,000 troops from Missouri to take up arms against the Confederacy, Jackson withdrew his support for neutrality. A subsequent meeting between Jackson and Union Brigadier General Nathaniel Lyon failed to resolve the matter. Instead, Lyon's Army of the West and the Missouri State Guard, commanded by former Missouri Governor Sterling Price, engaged in a series of minor battles during the summer of 1861 for control of the state.
By mid-June, after the Battle of Boonville, Lyon's army had driven Price's forces into the southwestern corner of Missouri, where they received reinforcements from other southern states. Brigadier General Ben McCulloch commanded the newly-formed, combined Confederate force. Rather than stand by and watch McCulloch's army continue to grow, Lyon determined to go on the offensive. On August 9, 1861, he led approximately 5,400 Union soldiers out of Springfield, Missouri to assault over 11,000 Rebels encamped near Wilson's Creek, approximately twelve miles southwest of the city.
Lyon's surprise attack, on the morning of August 10, caught the Confederates off guard. The Federals initially drove the Rebels back, but the Southerners eventually formed battle lines and halted the Union advance. The Confederates launched three counterattacks during the day, but despite being outnumbered over two to one, the Federals held their ground. During the course of the battle, Lyon was killed, and Major Samuel D. Sturgis took command of the Union army. As the day progressed, the exhausted Federals ran low on ammunition, so Sturgis ordered a retreat to Springfield. The Rebels were too spent to pursue.
Casualties at the Battle of Wilson's Creek were fairly even. The Union army suffered approximately 1,300 casualties, including 258 killed. The Confederate army suffered about 1,200 casualties, including 279 killed. The Confederate victory at the Battle of Wilson's Creek buoyed secessionist sympathies in Missouri and emboldened the Confederates to launch an offensive to regain control of northern Missouri. Secessionists formed a government and formally joined the Confederate cause, but they failed to garner the support of the majority of Missourians. After Union victories at the Battle of Fredericktown (October 21, 1861) and the Battle of Springfield (October 25, 1861), Jackson, Price, and their unofficial Confederate government were forced to abandon the state.
No exclusively Ohio units participated in the Battle of Wilson’s Creek.