Timeline of Missouri History: 1830-1849
| 1835 | Writer Samuel L. Clemens (Mark Twain) was born in Florida, Missouri (Nov. 30) | |
| 1836 | Missouri State Penitentiary received its first prisoner (Mar. 8) | |
| 1837 | President Martin Van Buren issued a proclamation which completed the annexation of the Platte Purchase area to Missouri, establishing the northwestern border of the state (Mar. 28) |  The Gregory School, Bollinger Co, Mo. 1916 |
| 1837 | Missouri’s first capitol in Jefferson City was destroyed by fire (Nov. 15) | |
| 1838 | Governor Lilburn Boggs issued the "Extermination Order" against Mormons living in Missouri, demanding that members of the Mormon church leave the state (Oct. 27) | |
| 1839 | The Geyer Act, the foundation of Missouri’s public school system, was approved (Feb. 9) | |
| 1841 | The University of Missouri, the first state university west of the Mississippi River, opened (Apr. 14) | |
| 1843 | Joseph Robidoux filed a plat of a town which he called St. Joseph (Jul. 26) | |
| 1843 | Susan Elizabeth Blow, founder of the public kindergarten movement, was born in St. Louis (June 7) | |
| 1847 | Legislation was enacted to establish a hospital for care and treatment of the insane; State Hospital No. 1 was established in Fulton and began receiving patients in 1851 | |
| 1847 | Boatmen’s Bank, the oldest bank west of the Mississippi River, was established (Oct. 18) | |
| 1847 | St. Louis was connected to the East Coast by telegraph (Dec. 20) | |
| 1849 | With the discovery of gold in California, the Missouri towns of St. Louis, Independence, Westport, and St. Joseph became points of departure for emigrants bound for California, making Missouri the "Gateway to the West" | |
| 1849 | The second, and most serious, cholera epidemic struck St. Louis; over 4000 people died | |