The Missouri State Militia was a federally funded state militia organization of Missouri conceived in 1861 and beginning service in 1862 during the American Civil War. It was a full-time force whose primary purpose was to conduct offensive operations against Confederate guerrillas and recruiters as well as oppose raids by regular Confederate forces. The militia at one time numbered more than 13,000 soldiers, but this force was reduced to 10,000 soldiers, by the United States government.