The Northwest Ordinance was passed in 1787 to organize United States territory north of the Ohio River.
The Confederation Congress adopted the ordinance on July 13, 1787, while the Constitutional Convention was meeting in Philadelphia. It created a system for governing the Northwest Territory and established a path by which territories could become states on an equal footing with existing states.
The ordinance described a territorial government, set population thresholds for statehood, and reserved certain rights, including trial by jury and freedom of religion. It also prohibited slavery in the Northwest Territory, making it an important early federal restriction on slavery’s expansion.
The territory eventually produced Ohio, Indiana, Illinois, Michigan, Wisconsin, and part of Minnesota. The ordinance is sometimes confused with the Land Ordinance of 1785, which established a surveying system for western lands. Together, the two measures helped the new nation manage expansion under the Articles of Confederation before the Constitution took effect.