This article: By the late 17th century, much of North America had been claimed by European countries. Spain had claimed Florida as well as modern-day Mexico and much of the southwestern part of the continent. The northern and central Atlantic coast was claimed by Britain, and New France comprised much of what is now eastern Canada as well as the central Illinois Country. The French feared that their territory was vulnerable to the expansionist aims of its neighbors. In 1681, French nobleman Robert Cavelier de La Salle launched an expedition down the Mississippi River from New France, at first believing he would find a path to the Pacific Ocean. Instead, La Salle found a route to the Gulf of Mexico. Although Hernando De Soto had explored and claimed this area for Spain 140 years before, on April 9, 1682, La Salle claimed the Mississippi River valley for French king Louis XIV, naming the territory Louisiana in his honor.Unless France established a base at the mouth of the Mississippi, Spain would have an opportunity to control the entire Gulf of Mexico and potentially pose a threat to New France's southern borders. La Salle believed that the Mississippi River was near the eastern edge of New Spain. On his return to France in 1684, he proposed to the Crown the establishment of a colony at the mouth of the river. The colony could provide a base for promoting Christianity among the native peoples as well as a convenient location for attacking the Spanish province of Nueva Vizcaya and gaining control of its lucrative silver mines. He argued that a small number of Frenchmen could successfully invade New Spain by allying themselves with some of the more than 15,000 Native Americans who were angry over Spanish enslavement. After Spain declared war on France in October 1667, King Louis agreed to support La Salle's plan. He was to return to North America and confirm "the Indians' allegiance to the crown, leading them to the true faith, and maintaining intertribal peace". contains an answer for the question: What year did the country that claimed Florida declare war on France?, what is it ?


1667