A map of the United States and territories east of the Mississippi River in 1790, showing the areas of freedom and slavery at the time, including the territory of the Northwest, free by the Ordinance of 1787.

The Ohio Valley and Great Lakes region after the French and Indian War (1754-1763). The Northwest Ordinance of 1787 was the first organization of land in the United States after the first 13 colonies. This ordinance set the important...