The history of Ohio as a state began when the Northwest Territory was divided in 1800, and the remainder reorganized for admission to the union on March 1, 1803 as the 17th state of the United States. The recorded history of Ohio began in the late 17th century when French explorers from Canada reached the Ohio River, from which the "Ohio Country" took its name, a river the Iroquois called O-y-o, "great river". Before that, Native Americans speaking Algonquin languages had inhabited Ohio and the central midwestern United States for hundreds of years, until displaced by the Iroquois in the latter part of the 17th century. Other cultures not generally identified as "Indians", including the Hopewell "mound builders", preceded them. Human history in Ohio began a few millennia after formation of