Congress enacted the Northwest Ordinance on July 13, 1787.
Formally titled An Ordinance for the Government of the Territory of the United States, North-West of the River Ohio, the law created the Northwest Territory. It covered land north of the Ohio River and east of the Mississippi River, including territory that later became several Midwestern states.
The ordinance established a process for territorial government and eventual statehood. It also prohibited slavery in the Northwest Territory, guaranteed certain legal rights, and encouraged education. Its approach created a model in which new states could join the Union on an equal footing with existing states.
The law is sometimes confused with the Land Ordinance of 1785, which primarily addressed surveying and selling western lands. It is also separate from the 1787 Constitutional Convention, held during the same year. The Confederation Congress passed the Northwest Ordinance before the Constitution took effect, and the First Congress later reaffirmed it with modifications.