The purpose of the study is a non-trivial theory about the causes of the emergence, growth, development and disappearance of the Kalusa people and its neighbors based on the materials currently available to the author. At the same time, unlike many other works, the author tried to take into account all the events in the New World and the Old World that influenced this process. A disinterested and objective view of the events was also given, free from religious, political and racial conventions. When collecting the material, it was analyzed and compared the culture and social structure of the disappeared Kalusa tribe, as well as its interaction with other peoples and cultures of North America and European civilizations in the XVI-XVIII centuries. He also gave his own view on the famous myth of the "Fountain of Youth" and its nature of origin.