Ohio is a Midwestern state of the United States. As part of the Great Lakes region, Ohio has long been a cultural and geographical crossroads in North America. At the time of European contact, and in the years that followed, Native Americans in the current territory of Ohio included the Shawnee, Iroquois, Miamis, and Wyandots. Starting in the 1700s, the area was settled by people from New England, the Mid-Atlantic States, Appalachia, and the Upper South.
Prior to 1984, the United States Census Bureau classified Ohio as part of the North Central Region.
That region was subsequently renamed as "Midwest" and divided into two divisions. Ohio is now in the East North Central States division. Ohio has the highest population density of any state outside of the Eastern Seaboard, and it is the seventh-largest U.S. state according to population.
Ohio was the first state admitted to the Union under the Northwest Ordinance. Its U.S. postal abbreviation is OH; its old-style abbreviation was O. Natives of Ohio are known as Ohioans or Buckeyes, after the buckeye tree.