The United States Congress passed the Northwest Ordinance governing the Northwest Territory in 1787.
The Confederation Congress adopted the measure on July 13, 1787, while delegates were meeting in Philadelphia to write the Constitution. It organized lands north of the Ohio River and east of the Mississippi River, an area that later became several Midwestern states.
The ordinance established a territorial government and described a path toward statehood. Once a territory reached a sufficient population, it could form a constitution and seek admission on an equal footing with existing states rather than becoming a permanent colony.
The measure also prohibited slavery in the Northwest Territory, although it did not immediately free enslaved people already held there. It protected religious freedom, encouraged education, and promised jury trials. The ordinance became a major model for later American territorial expansion and state admission.