Which 1787 law organized U.S. territory north of the Ohio River and prohibited slavery there?

The Northwest Ordinance of 1787 organized U.S. territory north of the Ohio River and prohibited slavery there.

The Confederation Congress adopted the measure on July 13, 1787, while delegates were meeting in Philadelphia to write the Constitution. It created a process through which the Northwest Territory could develop from a federal territory into states. The territory eventually produced Ohio, Indiana, Illinois, Michigan, and Wisconsin.

The ordinance protected certain civil rights, encouraged public education, and required territorial governments to establish representative institutions. Its most famous provision barred slavery in the territory, although the law did not end slavery in states where it already existed and did not prevent all forms of coerced labor.

The ordinance is sometimes confused with the later Missouri Compromise or Kansas–Nebraska Act, which addressed slavery in different territories and periods. It was also important because it supplied a durable model for governing western territories before statehood.