Sedalia is a city located approximately 30 miles (48 km) south of the Missouri River and, as the county seat of Pettis County, Missouri, United States, it is the principal city of the Sedalia Micropolitan Statistical Area, which consists of Pettis County. As of the 2010 census, the city had a total population of 21,387. Sedalia is also the location of the Missouri State Fair and the Scott Joplin Ragtime Festival. U.S. Routes 50 and 65 intersect in the city.
Indigenous peoples lived along the Missouri River and its tributaries for thousands of years before European contact. Historians believe the entire area around Sedalia was long occupied by the Osage (among historical American Indian tribes). When the land was first settled by European Americans, bands of Shawnee, who had migrated from east of the Mississippi River, lived in the vicinity of Sedalia.
The area that became the European-American city of Sedalia was founded by General George Rappeen Smith (1804–1879), who also founded nearby Smithton, Missouri. He filed plans for the official record on November 30, 1857, and gave the area the name Sedville. The original plat included the land from today's Missouri Pacific Railroad south to Third Street.
The version jointly filed by General Smith and David W. Bouldin on October 16, 1860, displayed the city extending from Clay Street to the north and to Smith Street (today's Third Street) in the south, and from Missouri Street in the west to Washington Street in the east; and, although Smith and Bouldin predicted that the city would grow to the north, it grew in a southern direction.
During the American Civil War, the U.S. Army had an installation in the area, adding to its boomtown atmosphere of accelerated development as merchants and traders attracted to the military business came to the area.