On March 6, 1857, the United States Supreme Court issues a decision in the Dred Scott case, affirming the right of slave owners to take their slaves into the Western territories, thereby negating the doctrine of popular sovereignty and a severe blow to the newly created Republican Party.
The great debate in the 1850s was wither slavery should be allowed in the West. As part of the Compromise of 1850, the residents of newly created territories had popular sovereignty which meant they could decide the issue of slavery by vote. In 1854 in Kansas popular sovereignty became a violent matter that ultimately landed with the Supreme Court.
Dred Scott was a slave. His owner, an army doctor, spent time in Illinois, a free state, and Wisconsin, a free territory.
The debate before the Supreme Court was the matter of whether Dred Scott’s residence has any baring on his ownership. As can be the case today, the Supreme Court can be stacked favoring one ideology over another and at the time of the Dred Scott case, it was stacked in favor of the slave states. Five of the nine justices were from the South while another, Robert Grier of Pennsylvania, was staunchly pro-slavery. Chief Justice Roger B. Taney wrote the majority decision, which was issued on March 6, 1857. The court held that Scott was not free based on his residence in either Illinois or Wisconsin because he was not considered a person under the U.S. Constitution–in the opinion of the justices, black people were not considered citizens when the Constitution was drafted in 1787. According to Taney, Dred Scott was the property of his owner, and property could not be taken from a person without due process of law.
In fact, there were free black citizens of the United States in 1787, but Taney and the other justices were attempting to halt further debate on the issue of slavery in the territories. The decision inflamed regional tensions, which burned for another four years before exploding into the Civil War.