A big Eastern city of Missouri, more than 400 thousand population, Saint Louis is also the site of The third session of Olympic Games. Located in the middle reaches of the Mississippi River, the longest river of United States, almost at the geometric center of the United States, the geographical position has important strategic significance. The area that is French colony, city by the French king's name. The economic development of the United States is pushed by the eastern Atlantic coast to the west the wilderness areas, European colonists and later the stream of goods and people also constantly flock to the western region, American geographers often refer it as the gateway to the west.St. Louis Arc Arch is located in the center of the city,who is an inverted catenary, is also a symbol of the American west development, the spectacular parabolic stainless steel building, 192 meters high, was started in 1964 built in just two years after.