The first major battle west of the Mississippi River, the Battle of Wilson's Creek, is fought on August 10, 1861, with a Confederate victory.

Lyon, hearing of a large Rebel force moving against him, had moved on August 1 to intercept them.

His men had moved into position undetected on the night of August 9 and surprise the Confederates in the morning at Wilson's Creek, near Springfield.

Directing troops on foot leading his horse, Lyon is struck in the leg and his horse killed by a hail of bullets.

He is later struck again, grazed on the right side of his head.

Staggering to the rear with the aid of another officer, Lyon reforms for a second assault.

Taking a mount from an aide, he impetuously leads the charge of the 2nd Kansas and is killed by a bullet in the chest at close range; his Major Sturgis assumes command.

The Confederates under General Price launch a third unsuccessful assault upon ”Bloody Hill”; when they fall back to regroup, Sturgis orders a hasty retreat to Springfield, unpursued by the exhausted Confederates.

In six hours of fighting, the Federals have suffered 1,317 killed, wounded and missing.

The Confederate casualties are 1,230.

The Battle of Wilson's Creek, in which Lyon has earned the distinction of being the first general to die in the Civil War, is the second major land battle of the war.