Coronado wa s Spanish explorer that was hungry for wealth and glory. He was leading his army through the southern portions of North America in order to find gold. Some tribes he encountered were telling stories of a place called Quivira, where there was lot of gold. In order to find this place, Corornado took several natives with him to guide him to Quivira, and after long search, they reached the place. It was the home of the Quivirans, which later became known as Wichita. There was not gold though, not at all. The only thing that Coronado found were simple, agricultural villages, vast plains with very fertile soil, and lot of crops.
The Upper South sold and transported enslaved people to the Deep South where they needed workers. Both the Upper and Deep South grew different crops so they depended on each other for these crops.