Final answer:
The Dred Scott decision declared that African Americans could not be citizens, the Missouri Compromise was unconstitutional, and Congress couldn't bar slavery in U.S. territories, effectively protecting slavery under the Constitution.
Step-by-step explanation:
The Dred Scott Decision
The Dred Scott decision by the Supreme Court in the case of Dred Scott v. Sandford is a landmark case in American history with profound implications on the issue of slavery. The ruling declared that:
- African Americans were not citizens of the United States and, therefore, could not sue in federal court.
- The Missouri Compromise, which prohibited slavery in certain territories, was unconstitutional.
- Congress had no power to bar slavery in the territories of the United States.
As a result, the Court confirmed that slaves who lived in free territories did not become free upon returning to a slave state, that slavery was effectively protected under the Constitution as a form of private property, and that efforts to restrict its expansion into new territories were invalid.