Final answer:
The Northwest Ordinance limited the expansion of slavery in the Northwest Territory by prohibiting slavery in the region.
Step-by-step explanation:
The Northwest Ordinance was a law passed by the United States Congress in 1787 that established guidelines for the organization and admission of new states in the Northwest Territory. One of the provisions in the ordinance stated that slavery was prohibited in the Northwest Territory. This limited the expansion of slavery in the region because it prevented new states from being established as slave states.
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