The Ohio River drains into a fertile basin that measures 203,000 square miles (528,101 square kilometers)—stretching across Ohio, West Virginia, Indiana, Illinois, and Kentucky. The river is formed by the confluence of the Allegheny and Monongahela rivers at Pittsburgh, Pennsylvania. From there the Ohio flows southwest, forming the border between Ohio and West Virginia. The river then turns west-northwest to form the border between Ohio and Kentucky before turning southwest again between Indiana and Kentucky, and between Illinois and Kentucky. Navigable by barges its entire length of 975 miles (1,569 kilometers), the Ohio River empties into the Mississippi River at Cairo, Illinois. The region surrounding the Ohio River is rich farmland. Commercial cities—trade centers that grew as transportation along the principal waterway increased—also dot the region.
The Ohio was first seen in 1669 by a European, French explorer Sieur de La Salle (1643–1687). In the first half of the 1700s, traders traveled the Ohio River, finding the surrounding valley a plentiful hunting ground. The fur trade flourished, making the region a coveted possession for both the French and the British. Numerous battles were fought in the valley, including the French and Indian War (1754–1763), the last major conflict in North America before the American Revolution (1775–1783).
The Ohio River Valley passed to British control (from the French) in 1763. In 1783 it became part of the new republic of the United States. Four years later the U.S. government established the Northwest Territory (the present-day states of Ohio, Michigan, Indiana, Illinois, Wisconsin, and part of Minnesota). Soon many settlers traveled the Ohio River westward. By 1820, more than 60 steamboats plied the Ohio, which remained the main westward route into the region until 1825. Settlement of the Ohio River Valley was aided by the federally built National Road (completed 1852), New York's Erie Canal (1825), and by Pennsylvania's Main Line Canal (1837).
Two companies also helped develop the region. The first was the Ohio River Valley Company (sometimes called the Ohio Company of Virginia), formed in 1747 when England's King George II granted London merchants and landed Virginians 200,000 acres (81,000 hectares) west of the Allegheny Mountains. But conflicts with the French stymied British efforts to settle the region and the company failed. The Ohio Company of Associates was organized in 1786 in Boston, Massachusetts. Shares were sold to raise enough money to petition the Congress of the Confederation to purchase land beyond the Ohio River. Congress sold the company 750,000 acres (304,000 hectares) in what is today southeastern Ohio. In 1787 Congress passed the Northwest Ordinance, which set guidelines by which territories became states. The first settlement founded under the Northwest Ordinance was Marietta, Ohio, which was named the capital of the Northwest Territory in 1788. Within a year three more settlements were made in the territory. Ohio was admitted to the Union in 1803.
OHIO VALLEY. Since prehistoric times the Ohio River and its tributaries have served as a major conduit for human migration, linking the Atlantic seaboard and Appalachian Mountains and the Mississippi valley. Human occupation in the Ohio valley began over sixteen thousand years ago, and the region was home to a series of cultures: Paleo-Indian (before 9500 b.c.e.), Archaic (9500–3000 b.c.e.), late Archaic–early Woodland (3000–200 b.c.e.), middle Woodland (200 b.c.e.–500 c.e.), late Woodland (500–1600 c.e.), and late Prehistoric (c. 1400–1600). The middle Woodland Hopewell culture, centered in southern Ohio and characterized by earthworks, elaborate burial practices, and long-distance trade, is notable, as is the Fort Ancient culture (1400–1600), located in southern Ohio, northern Kentucky, and eastern Indiana. The valley was occupied by a number of protohistoric and historic Native American societies, some indigenous to the river drainage basin and others who migrated westward, displaced by European colonization in the east. The Native American societies included the Iroquois (especially Seneca, Erie [to 1656], and Mingo) in western Pennsylvania; the Delaware and Seneca in southern Pennsylvania and West Virginia; the Delaware, Miami, Ottawa, Shawnee, Seneca, and Wyandot in Ohio; the Miami in Indiana; and the Delaware and Shawnee in northern Kentucky. The Ohio takes it name from the Iroquois language and means "Great River."
Reputedly the first European to view the Allegheny and Ohio rivers was Robert Cavelier, Sieur de La Salle, in 1669–1670, but the evidence is questionable. Maps of the region frequently were created on the basis of secondhand data, notably Louis Jolliet's (Joliet's) rendition of 1674 and Jean-Baptiste Franquelin's map of 1682, which depicted the Ohio flowing into the Mississippi. The French called the Ohio "La Belle Rivière," and the explorer Pierre Joseph Céloron de Blainville made a historic trip down the Allegheny and Ohio to the Miami River in 1749, placing lead plates at the junctions of major tributaries that claimed the region for France. From 1744 to 1754 traders and land agents from Pennsylvania, such as Joseph Conrad Weiser and George Croghan, came into the Ohio valley, and Christopher Gist explored the region for the Virginia-based Ohio Company in 1750–1751. The strategic significance of the Ohio became evident during the contest between Britain and France for control of the interior of North America in the 1750s. The French built forts on the upper Ohio in Pennsylvania—Presque Isle (Erie), Le Boeuf (Waterford), Venango, and Duquesne at the Forks of the Ohio (Pittsburgh)—precipitating war in 1754. Fort Duquesne was taken by the British in 1758 and was renamed Fort Pitt. The French and Indian War (Seven Years' War) was ended by the Treaty of Paris in 1763, and the British gained control of the Ohio valley.
The American military leader George Rogers Clark led an expedition down the Ohio in 1778 and wrested control of British settlements in what are now Indiana and Illinois. The 1783 Treaty of Paris established the Ohio River as a major American Indian boundary, but Jay's Treaty of 1794 ceded the Ohio valley to the Americans. General Anthony Wayne's victory at Fallen Timbers in 1794 diminished Indian attacks. A majority of settlers entered the Ohio valley through the river's headwaters, and the river became the major transportation route to the west during the first half of the nineteenth century. During the War of 1812(1812–1815) settlers from the Ohio valley and Atlantic colonies united against the British and Indians. Increased commercial traffic on the Ohio led to the dynamic growth of Pittsburgh, Cincinnati, and Louisville, but the completion of the Erie Canal in 1825 slightly diminished the river as a commercial artery. By the 1840s the Ohio had become a dividing line between free and slave states. Steamboat transportation diminished as railroads became the primary means of transporting raw materials, general cargo, and passengers. Because of shipping accidents a U.S. Coast Guard station was established in Louisville at the treacherous Falls of the Ohio in 1881. Major flood control projects were initiated because of serious floods in 1847, 1884, 1913, and 1937. The river remains a major transportation artery, a distinct sectional dividing line in the United States, and a source of recreation and tourism.
Banta, Richard E. The Ohio. Rivers of America Series 39. New York: Rinehart, 1949; reprinted Lexington: University Press of Kentucky, 1998.
Reid, Robert L. Always a River: The Ohio River and the American Experience. Bloomington: Indiana University Press, 1991.