A river formed by the confluence of the Allegheny and Monongahela Rivers in western Pennsylvania and flowing about 1,580 km (980 mi) to the Mississippi River at Cairo in southern Illinois. The British and French contested control of the river until 1763.
The Ohio River is a 981-mile long river in the United States. It is located in the midwestern United States, flowing southwesterly from western Pennsylvania south of Lake Erie to its mouth on the Mississippi River at the southern tip of Illinois. Hope this helps :)
