St. Louis, Missouri, sits along the Mississippi River at the state’s eastern border, near its meeting point with the Missouri River. Covering 61.74 square miles, its boundaries have been unchanged since 1876. Known as the "Gateway to the West," St. Louis was central to U.S. westward expansion, symbolized by the Gateway Arch—a 630-foot stainless steel structure and the world’s tallest monument—located in the 86-acre Gateway Arch National Park along the downtown riverfront. Operating independently from any county under Missouri's laws, St. Louis adopted its charter in 1923, following incorporation as a town in 1809 and as a city in 1823, a governance structure still in place today.
