Northwest Ordinance
The Northwest Ordinance established a means and precedence by which the United States could expand westward. For a collection of former colonies, extremely sensitive—to say the least—to the fashion in which they'd been governed by England, this was a crucial piece of egaliterian legislation.

The final of four Ordinances was adopted by the Confederation Congress sitting in its last session, in 1787. In sum, the Northwest Ordinance dealt with the territory aquired from Great Britain in the aftermath of the war—land north of the Ohio River and east of Mississippi. It made four crucial promises to prospective states in this region.

First, that each would enter the union "on an equal footing with the original states." Second, that revenue generated from the sale of a portion of each township in the state would go to fund public education—the first instance of federal aid for education in American history. Third, "neither slavery nor involuntary servitude" were to be allowed. And four, that a good faith effort would be made to respect the Indians in the territory.

In time, the Northwest Territories would become the states of Ohio, Indiana, Illinois, Michigan, Wisconsin and Minnesota. While the last of the ordinances was the most ill-kept, the third would prove crucial to the future history of the country. By federal mandate, each of the states in the Northwest Territories entered the union slave-free—a fact that would weigh heavily against the institution of slavery for years, and would help bring about its ultimate end by providing vast resources to the War Between the States to come.