How did the northwest ordinance of 1787 affect slavery? it stopped slavery from spreading to that area. it prohibited teaching enslaved people how to read. it abolished slavery throughout the nation. it allowed enslaved people to settle in the west.

It stopped slavery from spreading to that area.

Explanation:

Slavery and  was illegal in the Northwest Territory, subsequently making the Ohio River a characteristic separating line between the free and slave conditions of the nation.

Under the Articles of Confederation, the intensity of the national government to possibly diminish servitude in the southern states was relatively nonexistent. The suspicion that would later characterize the parity of free and slave states was not yet in full power. Servitude being set up in Kentucky and Tennessee, it was additionally evident that the rest of the south would be permitted to receive that training without issue.

might be agreeing to participate ethically with other european nations in the slave trade

or notifying other european nations when taking possession   of african territories

b: the establishment clause  

b: socialism