IV.

History

Native Americans have occupied the Ohio Valley for about 15,000 years, traveling and trading on the river and its tributaries. About 2,000 years ago a people now known as the Hopewell developed an elaborate culture and extensive trading networks; their most prominent archaeological remains are burial mounds found throughout the region. In the 1700s the Ohio Valley was home to the Shawnee, Miami, Omaha, Erie, and Susquehannock. French explorer René Robert Cavelier, Sieur de La Salle, visited the river in 1669; he was probably the first European to do so. In 1778 American military leader George Rogers Clark led an expedition down the Ohio, gaining control of several British settlements in present-day Indiana and Illinois. Settlement of the valley proceeded rapidly in the early 1800s, and by the 1820s the Ohio was a major transportation route to the West, followed by migrants to Ohio, Indiana, Illinois, and points west. River traffic grew rapidly but diminished in the late 1800s as railroads replaced the river as the primary means of transporting general cargo.

The river has seen several large floods, including those in 1847, 1884, 1913, and 1937, the last being the largest flood ever recorded along much of the river. Since 1937 the number of flood-control reservoirs, flood walls, and levees throughout the basin has grown, and flood hazards have been reduced.