<P> French fur traders operated in the area, and France built forts along the Allegheny River . In 1669, René - Robert Cavelier, Sieur de La Salle, led an expedition of French traders who became the first Europeans to see the river . He traveled from Canada and entered the headwaters of the Ohio, traveling as far as the Falls of Ohio at present - day Louisville before turning back . He returned to explore the river again in other expeditions . An Italian cartographer traveling with him created the first map of the Ohio River . La Salle claimed the Ohio Valley for France . </P> <P> In 1749, Great Britain established the Ohio Company to settle and trade in the area . Exploration of the territory and trade with the Indians in the region near the Forks by British colonials from Pennsylvania and Virginia--both of which claimed the territory--led to conflict with the French . In 1763, following the Seven Years' War, France ceded the area to Britain . </P> <P> The 1768 Treaty of Fort Stanwix opened Kentucky to colonial settlement and established the Ohio River as a southern boundary for American Indian territory . In 1774, the Quebec Act restored the land east of the Mississippi River and north of the Ohio River to Quebec, in effect making the Ohio the southern boundary of Canada . This appeased the Canadien British subjects but angered the Thirteen Colonies . Lord Dunmore's War south of the Ohio river also contributed to giving the land north to Quebec to stop further encroachment of the British colonials on native land . During the American Revolution, in 1776 the British military engineer John Montrésor created a map of the river showing the strategic location of Fort Pitt, including specific navigational information about the Ohio River's rapids and tributaries in that area . However, the Treaty of Paris (1783) gave the entire Ohio Valley to the United States . </P> <P> The economic connection of the Ohio Country to the East was significantly increased in 1818 when the National Road being built westward from Cumberland, Maryland reached Wheeling, Virginia (now West Virginia), providing an easier overland connection from the Potomac River to the Ohio River . </P>

When did the us get the ohio river valley