Explain how the Northwest Ordinance effect slavery in the U.S. (Use Ohio Rlver in your answer)

An Ordinance for the Government of the Territory of the United States, North-West of the River Ohio, 1787. Considered one of the most important legislative acts of the Confederation Congress, the Northwest Ordinance also protected civil liberties and outlawed slavery in the new territories. ...

The theory that the states’ may vote against unfair laws.

Explanation:

One of the most important questions debated in the Webster-Hayne debates was the question of what the purpose of the Union was. Whig Senator Daniel Webster of Massachusetts believed that the Union had been created in order to promote the good of the whole. On the other hand, Democrat Senator Robert Y. Hayne of South Carolina believed that the sovereign and independent states created the Union with the sole purpose of promoting their own interests.

This conflict led to the question of what actions could the states take when dealing with unfair laws. It also created the theory that the states should have the right to vote against unfair laws.