Union Army of the West
The Union Army of the West was a Union Army in the Western Theater of the American Civil War. It was made up of only four brigades and operated in Missouri. It was formed shortly after May 10, 1861 and was disbanded on August 19, 1861. The Army of the West was commanded by Brigadier general Nathaniel Lyon until his death at the Battle of Wilson's Creek on August 10, 1861.