Missouri has been inhabited since at least 8000 B.C. Its earliest known peoples were prehistoric hunters. The Mound Builders, whose earthworks are found in many parts of the state, came several thousand years later. At the time of European exploration, the region was occupied by many Indian tribes. The most numerous and powerful were the Osage, who lived in the south and west. The Missouri, after whom the state was named, were in the north. )

Important dates in Missouri
1673 Father Jacques Marquette and Louis Jolliet were probably the first Europeans to see the mouth of the Missouri River.
1682 Rene-Robert Cavelier, Sieur de La Salle, claimed the Mississippi Valley, including Missouri, for France. He named the region Louisiana.
c. 1735 Settlers established Missouri's first permanent white settlement, at Ste. Genevieve.
1762 France gave the Louisiana region to Spain.
1764 Pierre Laclede Liguest and Rene Auguste Chouteau established St. Louis.
1800 Spain returned the Louisiana region to France.
1803 France sold the Louisiana region to the United States.
1812 The U.S. Congress made Missouri a territory.
1815 Indian attacks on Missouri settlements ended when the Indians and United States government officials signed a peace treaty at Portage des Sioux.
1821 Missouri became the 24th state on August 10.
1837 Missouri gained its six northwestern counties as a result of the Platte Purchase.
1854 Border warfare began between antislavery Kansans and proslavery Missourians.
1861-1865 Missouri became a battleground during the American Civil War.
1904 The Louisiana Purchase Exposition was held in St. Louis.
1931 Bagnell Dam on the Osage River was completed, forming the Lake of the Ozarks.
1945-1953 Harry S. Truman of Independence became the 33rd president of the United States.
1965 The last section of the stainless steel Gateway Arch was put in place in St. Louis. The nation's tallest monument, it is 630 feet (192 meters) high.
1993 Disastrous flooding in the Midwest caused billions of dollars in damage to Missouri crops and property.