From Ohio History Central
Rene Robert Cavelier Sieur de La Salle was a French explorer and the first European known to have seen the Ohio River. La Salle was born in Rouen, France in 1643. As a young man he studied to become a Jesuit priest but left the religious order due to his unwillingness to conform to Jesuit doctrine. In 1666 he immigrated to the French colonies in North America. He lived in Montreal where he became a small farmer and participated in the fur trade. In his free time, he also attempted to find a route through the New World to China. For the previous two hundred years, Europeans had searched for a fast water route to China to acquire the silks and spices produced there. The only known route was to sail around Africa. It was a long, dangerous and grueling trip. Christopher Columbus had dreamed of sailing westward to reach the East. La Salle also hoped to find a much shorter route to Asia through North America.
During the winter of 1668-1669, La Salle learned from several Iroquois Indians that a great river supposedly could be found in the interior of North America. The water flowed westward in the direction of China. It is unclear if the natives meant the Ohio River or the Mississippi River. La Salle was intrigued. In the summer of 1669, he left Montreal on his quest to find China. His party canoed down the St. Lawrence River to Lake Ontario and then proceeded overland. La Salle later claimed that he had reached the Ohio River and that he had traveled along it as far as modern-day Louisville, Kentucky. He is credited with being the first European to see the Ohio River.
La Salle spent the rest of his life continuing to explore the waterways in the middle of North America. He also acquired a sizable fortune through the fur trade with Native Americans in the Ohio Country and modern-day Canada. In 1682, he sailed the length of the Mississippi River. Upon reaching the Gulf of Mexico he proclaimed that the entire river valley now belonged to France. Shortly thereafter, he returned to France and received the King's permission to establish a French colony at the mouth of the Mississippi. The ships carrying the colonists set sail in 1684. They missed the mouth of the Mississippi River and landed in modern-day Texas instead. The ships returned to France, but La Salle and a small number of men remained behind to locate the Mississippi River. In 1687, his followers mutinied and killed their leader.
La Salle was one of the earliest and most important explorers of North America. Although he failed to find a new water route to China, his efforts greatly enhanced European knowledge of North America. His friendliness toward the Native Americans helped unite the Indians with the French. This alliance would hamper English attempts to move into North America's interior.