The history of Missouri begins with settlement of the region by indigenous people during the Paleo-Indian period beginning in about 12,000 BC. Subsequent periods of native life emerged until the 17th century. New France set up small settlements, and in 1803 Napoleonic France sold the area to the U.S. as part of the Louisiana Purchase. Statehood for Missouri came following a compromise in 1820 that allowed slavery. Settlement was rapid after 1820, aided by a network of rivers navigable by steamboats, centered in the dominant city St. Louis. It attracted European immigrants, especially Germans; the business community had a large Yankee element as well. The Civil War saw numerous small battles and control by the Union. After the war, its economy became more diverse, and railroads, centered in Kansas City, opened up new farmlands in the west. In the early 20th century Progressive reforms sought to modernize state and local government and minimize political corruption. During the 20th century, Missouri's economy diversified further, and it developed a balanced agricultural and economic sector. By the 21st century manufacturing was fading, as service industries grew, especially in medicine, education and tourism. Agriculture remained profitable, as the farms grew larger and fewer people lived on them.
In May 1673, Jesuit priest Jacques Marquette and French trader Louis Jolliet paddled down the Mississippi River in canoes along the area that would later become the state of Missouri.
During the late 1680s and 1690s, the French pursued colonization of central North America not only to promote trade, but also to thwart the efforts of England on the continent.Pierre Gabriel Marest, a Jesuit priest, in late 1700 established a mission on the west bank of the Mississippi at the mouth of the River Des Peres. Marest established his mission station with a handful of French settlers and a large band of the Kaskaskia people, who fled from the eastern Illinois Country to the station in the hope of receiving French protection from the Iroquois. The Mississippi-Missouri river system waterways were the main means of communication and transportation in the region.
During the 1710s, the French government again began to pursue a course of increased development of Louisiana. Boisbriand ordered the construction of Fort de Chartres about eighteen miles north of Kaskaskia as the base of operations and headquarters for the company in the area. After the construction of Fort de Chartres, the company directed a series of prospecting expeditions to an area 30 miles west of the Mississippi River in present-day Madison, St. Francois, and Washington counties. These mining operations generally focused on discovering either lead or silver ore. Despite severe financial losses in late 1720, in January 1722 the company's directors sent Étienne de Veniard, Sieur de Bourgmont to Missouri to protect the company's trade networks on the Missouri River from Spanish influence. In November 1723, Bourgmont and the party arrived in present-day Carroll County in northern Missouri, where they constructed Fort Orleans. Within a year, Bourgmont negotiated alliances with indigenous tribes along the Missouri River. The quick abandonment of the fort after its construction was necessitated by the general retreat on the part of the company after the financial losses of 1720, and in 1731, the company returned its charter and control of Louisiana to royal authority. During the 1730s and 1740s, French control over Missouri remained weak, and no permanent settlements existed on the western bank of the Mississippi River.