Rene-Robert Cavelier, known as Sieur de La Salle, was the first European explorer to traverse the entire Mississippi River to its mouth at the Gulf of Mexico. Originally groomed for the priesthood in France, La Salle would journey through America on five separate expeditions. Author David Aretha describes how the explorer claimed the Louisiana territory for France in 1682 and met his end at the hands of his own men. Details about La Salle's legacy...