The Northwest Ordinance of 1787 prohibited slavery in the U.S. territory north of the Ohio River.
The ordinance created the Northwest Territory, a large region that later contributed to the states of Ohio, Indiana, Illinois, Michigan, Wisconsin, and part of Minnesota. It established a process by which territories could form governments and eventually enter the Union as states.
Article 6 stated that slavery and involuntary servitude were prohibited in the territory, except as punishment for a crime. The provision did not immediately end slavery everywhere in the United States, and it did not apply to territories south of the Ohio River.
The ordinance also protected religious liberty, encouraged education, and recognized certain rights of inhabitants. Its territorial system became an important model for later U.S. expansion and state admission.