Final answer:
The Dred Scott Case, or Dred Scott v. Sandford, was the Supreme Court ruling that slaves are considered property and African Americans could not be citizens, negating the notion that residing in a free state conferred freedom upon a slave and declaring the Missouri Compromise unconstitutional.
Step-by-step explanation:
The Supreme Court case that ruled slaves are property, regardless of their location, and that African Americans could not be United States citizens, was known as The Dred Scott Case or formally Dred Scott v. Sandford. In this landmark case, the Supreme Court decision, led by Chief Justice Roger B.
Taney, declared that residence in a free territory did not make a slave free once he or she returned to slave territory, effectively stating that slaves were property of their owners. Moreover, the decision stated that Congress had no authority to prohibit slavery in the territories, which made the Missouri Compromise unconstitutional.