The Continental Congress passed the Northwest Ordinance in 1787 to govern the territory north and west of the Ohio River.
The ordinance created a process for organizing the Northwest Territory and eventually admitting new states on an equal footing with the original states. It established territorial government, encouraged public education, and described civil rights protections for settlers.
One of its most consequential provisions prohibited slavery in the territory, although the ordinance did not immediately eliminate slavery elsewhere and included a fugitive-slave clause. The region later produced the states of Ohio, Indiana, Illinois, Michigan, Wisconsin, and part of Minnesota.
The law was adopted under the Articles of Confederation, months before the Constitutional Convention completed the U.S. Constitution. Its approach to territorial expansion became an important model for later U.S. policies. The ordinance is sometimes confused with the Land Ordinance of 1785, which primarily established a survey system for western lands.