St. Louis (St. Louis, or SAINT LOUIS, meaning saint, usually a person can only get this title after death) is a large city in eastern Missouri, United States. Located on the middle reaches of the Mississippi River, the longest in the United States, in the center of the continental United States and almost at the geometric center of the United States. It has important strategic significance in terms of geographical location. This area was a French colony at that time, and the city was named after the king of France. The economic development of the United States advanced from the eastern Atlantic coast to the vast desolate area in the west. European colonists and later people and goods also continued to flow from here to the western area. American geographers often call this the gateway to the west.

Historically, St. Louis was a fur trading market port for Indians and the largest cattle market in the United States. It later developed into the center of the leather and shoe industry in the United States. In 1764, French adventurer and businessman Pierre Leclid came from New Orleans to the confluence of the Mississippi and Missouri Rivers, the birthplace of St. Louis. At that time, the French Empire was declining. With the desire to get rid of British colonists and establish the last French-style city, he established the early prototype of the city on the west bank of the Mississippi River. In memory of King St. Louis IX of France, the place was named St. Louis. From 1800, St. Louis experienced its initial prosperity and development. By 1850, it developed into a medium-sized city with a population of more than 161,000, making it the 11th largest city in the United States at that time.