<P> Louisiana (French: La Louisiane; La Louisiane française) or French Louisiana was an administrative district of New France . Under French control 1682 to 1762 and 1802 (nominally) to 1803, the area was named in honor of King Louis XIV, by French explorer René - Robert Cavelier, Sieur de la Salle . It originally covered an expansive territory that included most of the drainage basin of the Mississippi River and stretched from the Great Lakes to the Gulf of Mexico and from the Appalachian Mountains to the Rocky Mountains . </P> <P> Louisiana included two regions, now known as Upper Louisiana (French: la Haute - Louisiane), which began north of the Arkansas River, and Lower Louisiana (French: la Basse - Louisiane). The U.S. state of Louisiana is named for the historical region, although it is only a small part of the vast lands claimed by France . </P> <P> French exploration of the area began during the reign of Louis XIV, but French Louisiana was not greatly developed, due to a lack of human and financial resources . As a result of its defeat in the Seven Years' War, France was forced to cede the east part of the territory in 1763 to the victorious British, and the west part to Spain as compensation for Spain losing Florida . France regained sovereignty of the western territory in the secret Third Treaty of San Ildefonso of 1800 . But strained by obligations in Europe, Napoleon Bonaparte sold the territory to the United States in the Louisiana Purchase of 1803, ending France's presence in Louisiana . </P> <P> The United States ceded part of the Louisiana Purchase to the United Kingdom in the Treaty of 1818 . This section lies above the 49th parallel north in a part of present - day Alberta and Saskatchewan . </P>

How did the french regain control of the louisiana territory