Congress passed the Northwest Ordinance governing the first U.S. territory in 1787.
The Confederation Congress adopted the measure on July 13, 1787, while delegates were meeting in Philadelphia to draft the Constitution. It organized the Northwest Territory, the area north of the Ohio River and east of the Mississippi River, and established a process by which territories could become states.
The ordinance promised civil liberties, prohibited slavery in the territory, and encouraged public education. It also described a three-stage territorial government and set a population threshold for statehood. The territory eventually produced Ohio, Indiana, Illinois, Michigan, Wisconsin, and part of Minnesota.
The ordinance is sometimes confused with the Constitution because both date from 1787. They were separate documents: the Northwest Ordinance managed western lands, while the Constitution created the federal government that replaced the Articles of Confederation.