Final answer:
The 1857 Supreme Court Case ruling that declared slaves as property and nullified the Missouri Compromise was Dred Scott v. Sandford.
Step-by-step explanation:
The subject of this question is Social Studies, specifically related to the history of the United States.
The 1857 Supreme Court Case ruling in question is Dred Scott v. Sandford. This ruling declared that slaves were considered property and not citizens, and it also nullified the Missouri Compromise, which had previously restricted the expansion of slavery.
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