La Salle explored the Mississippi River, reaching the Gulf of Mexico in April 1682. He claimed the entire Mississippi Valley for France and named it “Louisiana” after King Louis XIV.
Rene Robert Cavelier, Sieur de La Salle (1643–1687) claimed the Mississippi Valley for France in 1682, having led an expedition down the Mississippi River to the Gulf of Mexico. La Salle was murdered five years later, during another expedition, in a mutiny by his own men.