The Mississippi River is the primary river, and second-longest river, of the largest drainage basin in the United States. From its traditional source of Lake Itasca in northern Minnesota, it flows generally south for 2,340 miles (3,766 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 main stem is entirely within the United States; the total drainage basin is 1,151,000 sq mi (2,980,000 km2), of which only about one percent is in Canada. The Mississippi ranks as the thirteenth-largest river by discharge in the world. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana.

The United States of America, commonly known as the United States or America, is a country primarily located in North America. It is a federation of 50 states, a federal capital district, and 326 Indian reservations. Outside the union of states, it asserts sovereignty over five major unincorporated island territories and various uninhabited islands. The country has the world's third-largest land area, second-largest exclusive economic zone, and third-largest population, exceeding 334 million.