To appeal to as many voters as possible, politicians sometimes pronounce "Missouri" two different ways—Missouree and Missouruh—in the same speech. At one time, pronunciation correlated with geography, with the -uh sound being more prevalent in rural areas. Now it’s more of a generational difference.
Missouri was named after a tribe of Sioux Indians called the Missouris. While often mistranslated as “muddy water,” the word actually means “town of the large canoes.”
Missouri Revised Statutes, Chapter 9 (Public Holidays), Section 9.040.1:
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. (RSMo 1939 § 15316, A.L. 1957 p. 725, A.L. 1969 S.B. 70)
Interesting facts about Missouri: Harry Truman was the only U.S. President to hail from Missouri. Famous Missourian writers include T.S. Eliot, Maya Angelou, Mark Twain, Tennessee Williams, and Sara Teasdale. The 1904 World’s Fair in St. Louis introduced the masses to a number of new treats, including the waffle cone, cotton candy, iced tea, and Dr Pepper. The first successful parachute jump from a moving plane was made above the Jefferson Barracks military post, near St. Louis, on March 1, 1912. U.S. Army Captain Albert Berry climbed to 1,500 feet in a Benoist aircraft before positioning himself on a trapeze bar attached to the front of the plane, his parachute stored in a conical pack attached to his harness, and jumped. Missouri is one of 12 states with its own official horse. The Missouri Fox Trotter is a mid-sized muscular breed from the Ozarks that’s popular on ranches.
In 2017 Missouri Day in USA falls on October 18.