first european known to have crossed the mississippi river (2 wds.)
Hernando de Soto Hernando de Soto (c. 1495 â€“ 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, Mississippi, Alabama and most likely Arkansas). He is the first European documented as having crossed the Mississippi River.[4]