Mo. Rev. Stat. § 9.040

The third Wednesday of October of each year is known and designated as "Missouri Day" and is set apart as a day commemorative of Missouri history to be observed by the teachers and pupils of schools with the appropriate exercises. The people of the state of Missouri, and the educational, commercial, political, civic, religious and fraternal organizations of the state of Missouri are requested to devote some part of the day to the methodical consideration of the products of the mines, fields, and forests of the state and to the consideration of the achievements of the sons and daughters of Missouri in commerce, literature, statesmanship, science and art, and in other departments of activity in which the state has rendered service to mankind.