500 to 1500 The Mississippian people build large earthen mounds throughout Missouri.
1673 French explorers Father Jacques Marquette and Louis Jolliet enter Missouri.
1682 Robert de La Salle claims the Louisiana Territory for France.
1724 Fort Orleans is constructed.
1735 Settlers from Illinois establish the first settlement in Missouri Sainte Genevieve.
1764 The city of St. Louis is established.
1803 The United States buys Missouri as part of the Louisiana Purchase.
1804 Lewis and Clark leave St. Louis following the Missouri River on their trip to the Pacific Ocean.
1812 The Missouri Territory is established.
1821 Missouri is admitted to the Union as the 24th state.
1821 The Santa Fe Trail opens from Missouri to New Mexico.
1826 Jefferson City becomes the state capital.
1840s Thousands of settlers take the Oregon Trail from Missouri to the west coast.
1858 Missouri slave Dredd Scott is denied freedom in the Supreme Court decision that bears his name.
1861 A number of battles took place across Missouri that resulted in Union dominance of the state.
1865 Slavery is abolished in the state prior to the end of the Civil War.
1882 Jesse James the infamous bank robber was killed in St Joseph.
1905 The world's first gas station is built in St. Louis.
1945 Harry S. Truman becomes President of the United States.
1965 The Gateway Arch commemorating Missouri as the gateway to the west is completed.