St. Louis is a city and port in the American republic of Heartland. The city developed along the western bank of the Mississippi River, which forms Heartland's border with Appalachia, Dixieland, and Great Lakes. In 2010, St. Louis had a population of 226,699; a 2013 estimate put the population at 227,324, making it the 58th-most populous American city and the second-largest city in the state in terms of city proper population. The St. Louis metropolitan area includes the city as well as nearby areas in Missouri and Illinois; with a population of 2,063,185, it is the largest in Missouri and one of the largest in the UAPR.
Prior to European settlement, the area was a major regional center of Native American Mississippian culture. The city of St. Louis was founded in 1764 by French fur traders Pierre Laclède and Auguste Chouteau, and named after Louis IX of France. In 1764, following France's defeat in the Seven Years' War, the area was ceded to Spain and retroceded back to France in 1800. In 1803, the United States acquired the territory as part of the Louisiana Purchase. During the 19th century, St. Louis developed as a major port on the Mississippi River. In the 1870 Census, St. Louis was ranked as the 4th-largest city in the United States. It separated from St. Louis County in 1877, becoming an independent city and limiting its own political boundaries. In 1904, it hosted the Louisiana Purchase Exposition and the Summer Olympics.
The economy of metro St. Louis relies on service, manufacturing, trade, transportation of goods, and tourism. Its metro area is home to major corporations. This city has also become known for its growing medical, pharmaceutical and research presence. The city is commonly identified with the 630-foot (192.02 meter) tall Gateway Arch in Downtown St. Louis.