when was ohio annexed?

Answer 1

The United States won this region during the American Revolution. Following the Treaty of Paris (1783), Congress created the Northwest Territory north of the Ohio River and enacted the Ordinance of 1785, which established an orderly settlement pattern, and subsequently the Northwest Ordinance of 1787, which called for the creation of new states there. Ohio achieved statehood in 1803.

Answer 2

What do you mean annexed? Ohio became the 17th US state in 1803. It was part of the Connecticut Western Reserve Company.