Mississippi River in St Paul, Minnesota Since 2006 I have spent a large portion of my life in the USA. During that time it has been my good fortune to have visited 45 of the 50 states that comprise the USA, and while doing so I have crossed and walked the banks of the great Mississippi River a number of times. This river is the second longest river in the USA. Its source is at Lake Itasca in Minnesota, and it flows 2320 miles from there to its mouth in the Gulf of Mexico. It is also divided into what is known as the upper Mississippi, from its source south to the Ohio River, and the lower Mississippi, from the Ohio to its mouth near New Orleans, Louisiana This mighty river runs through, or along 10 states, from Minnesota to Louisiana, and was used to define portions of these states' borders, with Wisconsin, Illinois, Kentucky, Tennessee, and Mississippi along the east side of the river, and Iowa, Missouri, and Arkansas and Louisiana along its west side. In 20