The process of admitting the Missouri into the Union of the United States of America in 1820 and '21 was a complicated endeavor. The complications of the admission included slavery and keeping a balance in representation between the free and slave states in the United States Congress. The admission of Missouri into the Union was further complicated by the state's first constitution written in 38 days between June 12 and July 19, 1820, during a consititutional convention that took place in the City of St. Louis. A small portion of Missouri's first governing document was viewed by Congress as problematic. However, Congress passed a resolution admitting Missouri into the Union under a “fundemental condition” that had to be addressed by the state legislature, known as the “General Assembly”, in “a solemn public act”. This “solemn public act” was approved by the General Assembly, under protest, in June of 1821. On August 10, 1821 without further action from Congress, the President of the United States (at the time), James Monroe, declared in an official proclamation that Missouri was admitted into the Union, as the 24th state of the United States of America.
Since Missouri became a State of the United States of America, its' government has functioned under four constitutions: the 1820, the 1865, the 1875 and the, current, 1945. The current constitution was written during a constitutional convention that occurred in Jefferson City between September 1943 and September 1944. The citizens of the state voted upon and ratified the proposed constitution on February 27, 1945. Since that time, the 1945 Constitution has been amended numerous occassions.
At left are links to the texts of the documents that made Missouri's admission into the Union a reality. Sources for “The Statehood Documents of Missouri” can be found here while information about Missouri's state flag can be found by clicking on either state flag at the top of this page.