Nathaniel Lyon was born in Connecticut in 1818 and graduated from the United States Military Academy at West Point in 1841. He fought in the second Seminole War and the war with Mexico. After the Mexican War he served in California and was stationed at Fort Riley, Kansas, where the political climate predicted the coming sectional conflict. A strict, perhaps severe, disciplinarian he was considered impetuous and hot-headed by some.
In February 1861, after the secession winter but before open hostilities, Nathaniel Lyon was assigned to command the federal weapons arsenal in St. Louis. Tension was high for Governor Claiborne Fox Jackson was an avowed southern sympathizer and secessionist. When war began in April and Lincoln called for troops, including 4 regiments from Missouri, Jackson refused. Rather, he assembled the state militia outside at the fairgrounds outside St. Louis in anticipation of fighting for the south. On May 10, Lyon sent troops to surround and subdue the militia. After capturing the militia and while marching them through St. Louis, pro-southern citizens began to riot. Lyon ordered the troops to defend themselves and they fired into the crowd, killing 28.
A week later, Lyon was given command of all Union troops in Missouri. Shortly after, in a fiery meeting, he and Congressman Francis P. Blair met with Governor Jackson and General Sterling Price in peace negotiations. The meeting failed as Lyon stated, “Rather than concede to the state of Missouri the right to dictate to my government in any matter however unimportant, I would see you, and you, and every man, woman, and child in the state dead and buried. This means war.”
Forcing the Missouri State Guard, their leaders, Price and Gov. Jackson, west, Union forces captured Jefferson City, won the first battle of Boonville on June 17th, gained control of the Missouri River and secured most of northern Missouri.
After refitting, recruiting and reorganizing, and uniting with soldiers under Col. Franz Sigel, Lyon’s troops attacked Price, the Missouri State Guard and Confederate regular army troops just south of Springfield at Wilson Creek on August 10. While rallying his outnumbered men, Lyon was shot through the heart and died instantly, the first Union general to die in the conflict.
Lyon’s efforts kept Missouri in the Union. Ironically, the efficiency in clearing northern Missouri of the Guard and regular CSA troops left many pro-southern men behind Union lines and laid the groundwork for the deadly guerilla war that lasted the rest of the war.