They seized the small Federal armory in Liberty, Missouri, planning to subsequently confiscate a much more sizable stock of weapons located at the St. Louis Arsenal.

Lyon allied himself with Missouri Congressman Frank Blair and anti-slavery German immigrants in St. Louis to secure the arsenal for the Union.

[3] The new State Guard began organizing statewide in nine decentralized military districts, initially structured around the independent militia companies of the pre-Camp Jackson MVM.

Jackson demanded that Federal forces remain isolated in St. Louis and that pro-Unionist Home Guard companies of Missouri Unionists around the state be disbanded.

General Lyon promptly set out after them by steamboat, with two Federal volunteer regiments, a company of U.S. regulars and a battery of artillery — about 1,700 men in all.

Many of his men were eager to face the enemy, but they were armed only with shotguns and hunting rifles, and lacked sufficient training to fight effectively at the time.

Informed of Lyon's approach, Jackson attempted to call up Parsons' command at Tipton, but it was unable to arrive in time.

Some attempts were made to rally and resist the Federal advance, but these collapsed when a Union company flanked the Guard's line, supported by cannon fire from a light howitzer on the river steamer Augustus McDowell.

The guardsmen fled back through Camp Bacon and the town of Boonville; some continued on to their homes, while the rest retreated with the Governor to the southwest corner of Missouri.

Lyon seized the State Guard's supplies and equipment, which included two iron 6-pounder cannons without ammunition, 500 obsolete flintlock muskets, 1,200 pairs of shoes, a few tents, and food.

Federal casualties and sources: Sergeant Jacob Kiburz, Private Marcus M. Coolidge, Charles O. Kelly were recorded as killed or mortally wounded.

Missouri State Guard casualties and sources: Jeff McCutchen, Dr. William Mills Quarles, Isaac Hodges, Frank E. Hulen, and Mr. Woods were named as killed or mortally wounded.

Lane Bynam, Robert Withers, Clay Bredlove, William Brown, 1st Lt R. H. Carter, Tip Garth, John Henderson, W. T. Marshall, Mr. Miller, and W. B. Napton Jr, are the named wounded.

While the Missouri State Guard would fight and win on other days (most notably at Wilson's Creek and Lexington just two and three months later, respectively), it was badly dispirited by this early defeat.

Due to rain, the Confederates wrapped their flags in black sheathing, which the Home Guard mistook as a sign of no quarter.

Highly motivated by a perception that the fight was one of "victory or death", the Home Guardsmen managed to defeat the State Guard troops, killing Colonel Brown in the process.

The Fourth Battle of Boonville was fought on October 11, 1864 between Unionists and elements of General Sterling Price's Army of Missouri, who had occupied the town.