David C. King, Norman McRae, and Jaye Zola, The United States and Its People (Menlo Park, CA: Addison-Wesley Publishing Company, 1993), 295.
The case of Dred Scott v. Sandford reached the Supreme Court in March 1857. By a vote of seven to two, the Court ruled that black people - either free or enslaved - were not citizens of the United States and, therefore did not have the right to sue in a federal court. Dred Scott thus would have to remain enslaved, subject to the laws of the state of Missouri...Southerners rejoiced at the Dred Scott decision, which opened all territories to slavery. The North was outraged at the decision. The Republican party had dedicated itself to preventing the extension of slavery. Now, it seemed, slavery could be extended throughout the territories.