On August 10, 1821, Missouri was admitted to the union as the 24th state. From the article:
"General Missouri State History
Father Jacques Marquette and Louis Joliet, who descended the Mississippi from the North in 1673, supplied the first written accounts of exploration in Missouri. The early Indians in Missouri were the Osages, Sacs, Foxes, Otos, Iowas, Missouris, Miamis, Kickapoos, Delawares, Shawnees and Kansas. Although named for an Indian tribe, today there are no organized tribes left in Missouri.
As part of the Louisiana Purchase territory, Missouri has belonged to three nations: France, Spain and the United States. First claimed for France by LaSalle in 1682, Missouri was ceded to Spain in 1762. Although Spain held the country for 40 years, its in influence was slight.
The early development of Missouri was closely associated with lead mining. Galena, a lead ore, was first discovered in 1701 near Potosi and began to be mined in earnest in 1720 upon the discovery of significant deposits at Mine La Motte. Mining, the earliest commercial activity in Missouri, lured early French settlers and continues to be a major enterprise today.
It was the French who were responsible for the first permanent settlement of Ste. Genevieve in the mid-1730s. This settlement alone in the huge Upper Louisiana Territory until the establishment of St. Louis as a fur trading post in 1764. Because of its excellent location where the Missouri River flows into the Mississippi, St. Louis became the largest settlement in the state and today is one of the nation's larger cities.
By secret treaty in 1802, Spain ceded the Louisiana Territory back to France. Napoleon Bonaparte, anxious to rid himself of the vast and troublesome frontier, sold it to the United States in 1803 for a total of $15,000,000. About this time President Jefferson organized the Lewis and Clark Expedition which was the first extensive exploration of the northwestern part of the new territory. The expedition left St. Louis in 1804. Missouri was organized as a territory in 1812 and was admitted to the Union as the 24th state on August 10, 1821. Missouri was the second state (after Louisiana) of the Louisiana Purchase to be admitted to the Union.
In 1820, the Missouri Compromise was passed whereby Missouri was to be admitted as a slave state and Maine as a free state. Although admitted as a slave state, Missouri nevertheless remained with the Union throughout the Civil War.
At the beginning of the Civil War, most Missourians wanted only to preserve the peace. However, the state governor, Claiborne Fox Jackson, was strongly pro-southern and attempted to align Missouri with the Confederacy. He and most of the legislature were forced to flee to southern Missouri where they actually passed an ordinance of secession. However, this government was no longer recognized by most Missourians.
The most important and bloodiest battle fought in Missouri was the Battle of Wilson's Creek near Springfield. Other important battles in Missouri were fought at Carthage, Lexington, Westport and Boonville - the first engagement within the state. Missouri contributed 109,000 men to the northern cause while sending at least 30,000 men into the Confederate ranks.
During World War I, Missouri provided 140,257 soldiers, one-third being volunteers. Missouri contributed such notable leaders as Gen. John J. Pershing of laclede, commander of the American Expeditionary Forces in Europe, and Provost Marshall Enoch H. Crowser of Grundy County who drew up the Selective Service Act.
During World War II, Missouri contributed a total of over 450,000 men and women to the various armed forces. Eighty-nine top officers were from Missouri including Gen. Omar N. Bradley of Clark and Moberly and Lt. Gen. James H. Doolittle of St. Louis.
The nation's leader during the last year of the war was Lamar-born Harry S Truman, first Missourian to become President of the United States. After assuming office upon the death of Franklin D. Roosevelt in 1945, President Truman was re-elected to a full four-year term. His was the fateful decision to use the atom bomb and hasten the Japanese surrender consummated on the deck of the battleship USS Missouri in Tokyo Bay.
Missourians later served in the Korean and Vietnam wars and Dr. Thomas A. Dooley and Gen. Maxwell D. Taylor emerged as noted figures. Like the rest of the country, Missouri has moved toward the 21st century with modernized technology, nuclear energy, transportation, education; progress in civil rights and women's rights; and shifts in the economy and business outlook."