Why Famous: Led the first European expedition deep into the territory of the modern-day United States, and the first documented to have crossed the Mississippi River.
- 1539-05-30 Spanish explorer Hernando de Soto discovers Florida
- 1539-06-03 Hernando De Soto claims Florida for Spain
- 1540-06-03 Hernando de Soto crosses Appalachian Mountain, 1st European to do so
- 1541-03-18 Hernando de Soto observes 1st recorded flood in America (Mississippi River)
- 1541-05-08 Spanish explorer Hernando de Soto discovers the Mississippi River