St. Louis is an independent city and major U.S. port in the State of Missouri, built along the western bank of the Mississippi River, on the border with Illinois. The city has an estimated 2015 population of 315,685, and is the cultural and economic center of the Greater St. Louis area (home to 2,916,447 people), making it the largest metropolitan area in Missouri and the 19th-largest in the United States.
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. The area was ceded to Spain following France's defeat in the Seven Years' War (the area east of the Mississippi was ceded to Britain). In 1800, Spanish Louisiana was retroceded back to France. In 1803, the United States acquired the territory as part of the Louisiana Purchase.
After the Louisiana Purchase, St. Louis developed as a major port on the Mississippi River. In the late-19th century, 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. Immigration has increased, and the city is the center of the largest Bosnian population in the world outside their homeland.
The economy of metro St. Louis relies on service, manufacturing, trade, transportation of goods, and tourism. Its metro area is home to major corporations, including Anheuser-Busch, Express Scripts, Centene, Boeing Defense, Emerson, Energizer, Panera, Enterprise, Peabody Energy, Ameren, Ralcorp, Monsanto, Scottrade, Edward Jones, Go Jet, Purina and Sigma-Aldrich. This city has also become known for its growing medical, pharmaceutical and research presence. St. Louis has 2 professional sports teams: the St. Louis Cardinals of Major League Baseball and the St. Louis Blues of the National Hockey League. The city is commonly identified with the 630-foot (192 m) tall Gateway Arch in Downtown St. Louis.