The Missouri State Guard (MSG) was a state militia organized in the state of Missouri during the early days of the American Civil War. While not initially a formal part of the Confederate States Army, the State Guard fought alongside Confederate troops and, at times, under regular Confederate officers.

The Third District/Third Division was made up of troops from the counties of Putnam, Schuyler, , Sullivan, Adair, Linn, Macon, Chariton, Randolph, Howard, and Boone, and was led by John B. Clark, Sr.

From the Order of Battle at the Battle of Wilson's Creek:

Division, Brigade, & Regiments and Others

Third Division - BG John Bullock Clark, Jr

Burbridge's Infantry - Col John Q. Burbridge

Major's Cavalry - Ltc James P. Major