Northwest Territory

The Northwest Territory, also known as the Old Northwest and formally known as the Territory Northwest of the River Ohio, was formed in the United States after the American Revolutionary War. Established in 1787 by the Congress of the Confederation through the Northwest Ordinance, it was the nation's first post-colonial organized incorporated territory.

At the time of its creation, the territory included all the land west of Pennsylvania, northwest of the Ohio River and east of the Mississippi River below the Great Lakes. The region was ceded to the United States in the Treaty of Paris of 1783. Throughout the Revolutionary War, the region was part of the British Province of Quebec. It spanned all or large parts of six eventual U.S. States . Reduced to present-day Ohio, eastern Michigan and a sliver of southeastern Indiana with the formation of Indiana Territory July 4, 1800, it ceased to exist March 1, 1803, when the southeastern portion of the territory was admitted to the Union as the state of Ohio, and the remainder attached to Indiana Territory.

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