Why was la salle's expedition down the Mississippi River important to France?

The expeditions led to the establishment of an overland trade route connecting French colonies in Canada with French colonies in Louisiana. All of the land covered in the expedition was claimed on behalf of Louis XIV, King of France, and initiated a period of French control in the region that would last for nearly a century.

French claims extended from the St. Lawrence river down the mississippi river to the gulf of mexico.