Timeline of Missouri History: 1900-1929
| 1901 | The first State Fair held at Sedalia opened (Sept. 9) | |
| 1901 | The Monsanto Company was founded in St. Louis (Nov. 29) |  1904 Worlds Fair Varied Industries Building |
| 1904 | The 1904 World’s Fair opened in St. Louis (Apr. 30) | |
| 1907 | The primary election law was adopted in Missouri | |
| 1909 | Missouri Supreme Court handed down a decision in the case against Standard Oil Company, affirming the company’s violation of Missouri antitrust laws | |
| 1911 | Missouri State Capitol was completely destroyed by fire after being struck by lightning (Feb. 5) | |
| 1913 | Direct election of senators was authorized; previously, US senators from Missouri were elected by the General Assembly | |
| 1919 | Governor Frederick D. Gardner signed a law granting presidential suffrage to women (Apr. 5) | |
| 1919 | Missouri became the eleventh state to ratify the Nineteenth Amendment granting suffrage to women (Jul. 2) | |
| 1920 | The Nineteenth Amendment was added to the U. S. Constitution on August 26. Marie Byrum became the first woman to vote in Missouri history (Aug. 31) | |
| 1921 | The Centennial Road Law, providing for the construction of a modern system of Missouri highways, was signed into law (Aug. 4) | |
| 1922 | Mellcene T. Smith and Sarah Lucille Turner became the first women elected to the Missouri state legislature (Nov. 7) | |
| 1927 | Charles Lindbergh landed the "Spirit of St. Louis" in Paris (May 21) | |