New France
In 1763, France had ceded the rest of New France, except the islands of Saint Pierre and Miquelon, to Great Britain and Spain at the Treaty of Paris, which ended the Seven Years' War (known as the French and Indian War in North America and especially the United States). Britain received Canada, Acadia, and the parts of French Louisiana which lay east of the Mississippi Riverexcept for the Île d'Orléans, which was granted to Spain, along with the territory to the westthe larger portion of Louisiana.
New France
The French extended their territorial claim to the south and to the west of the American colonies late in the 17th century, naming it for King Louis XIV, as La Louisiane. In 1682, René-Robert Cavelier, Sieur de La Salle explored the Ohio River Valley and the Mississippi River Valley, and he claimed the entire territory for France as far south as the Gulf of Mexico. La Salle attempted to establish the first southern colony in the new territory in 1685, but inaccurate maps and navigational issues led him to instead establish his Fort Saint Louis in what is now Texas. The colony was devastated by disease, and the surviving settlers were killed in 1688, in an attack by the area's indigenous population. Other parts of Louisiana were settled and developed with success, such as New Orleans and southern Illinois, leaving a strong French influence in these areas long after the Louisiana Purchase.