The longest or second-longest in North America, depending on how you count. (The Missouri River could be considered longer.) Referred to by Abraham Lincoln as 'the father of waters,' the Mississippi begins at Lake Itasca, Minnesota, and flows 2,340 miles to a vast delta on the Gulf of Mexico, forming portions of ten state borders and the world's third-largest drainage basin. The Mississippi picks up numerous major tributaries including the Illinois, Missouri, Ohio, Arkansas, and Red Rivers, and flows past numerous major cities, including Minneapolis, St. Louis, Memphis, and New Orleans.