Hernando de Soto discovered the Mississippi River, in 1541. De Soto was the first explorer to voyage into the interior land of North America.
In 1539, European explorer Hernando de Soto embarked on a journey that no man had tried previously. With more than 600 men, de Soto traveled from what is now Tampa, Florida, to the southeastern region of the United States in hopes of finding gold and other treasure. The crew explored the areas that would become Florida, Georgia, Alabama, Tennessee, the Carolinas, Arkansas and Mississippi. During his journey, he discovered the Mississippi River, but de Soto also lost his life to a fever in the spring of 1542.