Hernando de Soto, a Spanish explorer who arrived in the early 16th century, is credited with mapping much of the southeastern United States. His expeditions took him through areas that are now part of Florida, Georgia, South Carolina, North Carolina, Tennessee, Alabama, Mississippi, Arkansas, and Louisiana. Although de Soto was seeking gold and wealth, his journeys provided crucial insights into the geography and indigenous societies of the region. His interactions with Native American tribes also had significant implications for the future of European colonization in North America.