Final answer:
In 1682, Rene-Robert Cavelier, Sieur de La Salle, canoed down the Mississippi River to its mouth at the Gulf of Mexico, contributing to the French colonization of the area and expanding European influence in North America.
Step-by-step explanation:
Rene-Robert Cavelier, Sieur de La Salle, a French explorer, canoed down the Mississippi River to its mouth at the Gulf of Mexico in 1682. La Salle's exploration of the Mississippi River played a significant role in the French colonization of the area and the subsequent territorial claims by the United States. His journey helped establish a crucial trade route and expand European influence in North America.