The Northwest Ordinance of 1787 established the Northwest Territory, the first organized incorporated territory of the United States.
Congress enacted the ordinance on July 13, 1787, under the Articles of Confederation. The territory lay north and west of the Ohio River, extending toward the Great Lakes and the upper Mississippi River. Its lands had been ceded by Great Britain in the Treaty of Paris, but the new United States needed a system for governing and settling them.
The ordinance created a path by which territories could become states rather than remaining permanent colonies. It provided for an appointed governor and, after population growth, an elected legislature. It also prohibited slavery in the territory, although the provision did not eliminate slavery elsewhere in the United States.
The territory eventually produced Ohio, Indiana, Illinois, Michigan, Wisconsin, and part of Minnesota. The Northwest Ordinance is often confused with the Land Ordinance of 1785, which primarily organized the surveying and sale of public land rather than creating a territorial government.