Hernando de Soto (c. 1500 – May 21, 1542) was a Spanish explorer and conquistador who led the first European expedition deep into the territory of the modern-day United States (Florida, Georgia, Alabama and most likely Arkansas), and the first documented European to have crossed the Mississippi River.
A vast undertaking, de Soto’s North American expedition ranged throughout the southeastern United States searching for gold, and a passage to China. De Soto died in 1542 on the banks of the Mississippi River in what is now Guachoya, Arkansas or Ferriday, Louisiana.
May 8 in Mississippi is declared to be Hernando de Soto Day in recognition, observation and commemoration of Hernando de Soto, who led the first and most imposing expedition ever made by Europeans into the wilds of North America and the State of Mississippi, and in further recognition of the Spanish explorer’s 187-day journey from the Tombigbee River basin on our state’s eastern boundary, westward to the place of discovery of the Mississippi River on May 8, 1541. This day is a day of commemoration, recognition and observation of Hernando de Soto and European exploration (but not recognized as a legal holiday).
Source: ms.gov | wikipedia.org