The Northwest Ordinance established a plan for governing U.S. territories in 1787.
Congress of the Confederation adopted the ordinance on July 13, 1787. It organized the Northwest Territory, the area north of the Ohio River and east of the Mississippi River, and created a process by which territories could eventually become states.
The ordinance provided for appointed territorial government at first, followed by greater self-government as population increased. It also banned slavery in the territory and protected certain civil and religious rights, although it did not end slavery elsewhere.
The Northwest Ordinance was important because it supplied a model for orderly expansion rather than leaving new lands under uncertain administration. The territory later contributed to the states of Ohio, Indiana, Illinois, Michigan, and Wisconsin, as well as part of Minnesota.