The Mississippi River is the primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for 2,340 mi (3,770 km) to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 32 U.S. states and two Canadian provinces between the Rocky and Appalachian mountains. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana. The main stem is entirely within the United States; the total drainage basin is 1,151,000 sq mi (2,980,000 km), of which only about one percent is in Canada. The Mississippi ranks as the world's tenth-largest river by discharge flow, and the largest in North America.
Native Americans have lived along the Mississippi River and its tributaries for thousands of years. Many were hunter-gatherers, but some, such as the Mound Builders, formed prolific agricultural and urban civilizations, and some practiced aquaculture. The arrival of Europeans in the 16th century changed the native way of life as first explorers, then settlers, ventured into the basin in increasing numbers. The river served sometimes as a barrier, forming borders for New Spain, New France, and the early United States, and throughout as a vital transportation artery and communications link. In the 19th century, during the height of the ideology of manifest destiny, the Mississippi and several tributaries, most notably its largest, the Ohio and Missouri, formed pathways for the western expansion of the United States. The river also became the subject of American literature, particularly in the writings of Mark Twain.
