Source: Michael Gannon, "The First Florida Mission; Mission San Francisco de Potano." St. Augustine Catholic, May, 2006: 7.

In San Miguel and San Francisco the Indians listened to the instruction and with great diligence learned the things of God that I taught them... [In another place] the Indians made fun of me. They jostled me when I announced Christian doctrine to them. One of them said: "Our cacique [chief] is very old. When he was a boy he was a captive of Hernando de Soto. From Christians he had received much injury and for this reason he tells us that we should not become Christians." At that moment there was a thunderclap so that all fell to the ground, accompanied by so strong a wind that in this place and in the other there remained neither a house nor a barn standing, nor a hut nor any structure, great or small. Only a cross and a church in which Mass had been said, remained standing, and this through the mercy of God, our Master. The next day the cacique called for me in order that I might instruct him. Within six days I baptized him and after that he gave his soul to God. The entire locality had the greatest desire of becoming Christians. I baptized there four hundred persons, old and young.

The mission lasted for a century. But it came to an end when the Potano people either died from European diseases or were killed by invading attackers from the Carolinas, who were reinforced by the Indian allies of the English slave owners.
Hernando de Soto undertook a disastrous journey of discovery and failed conquest through Florida in 1539-1540. He died on the Mississippi River in 1542. For a proposed map of de Soto's trip, see: => De Soto map. It is worth noting that Spanish missionaries later established missions throughout the region traversed by de Soto. These missions acted as Spain's putative legal claim to the American Southeast because they were "settlements on the ground," so to speak.