The question whether slavery should be allowed in territories acquired by the U.S. was a controversial one prior to the Civil War. Dred Scott, a slave, was taken by his master from Missouri (a slave state) first to Illinois (a free state) and then to Wisconsin Territory where slavery under the Missouri Compromise of 1820 was forbidden. Later, with his owner, Dred Scott returned to Missouri. Dred Scott and his wife filed a petition in a Missouri court requesting permission to file suit in order to establish their right to be freed since they had resided on free soil. After two trials and the Scotts temporarily winning their freedom, the Missouri Supreme Court reversed the lower court’s judgment and held that the Scotts’ residence on free soil had not changed their status as slaves. The Scotts then brought suit in a U. S. Circuit Court where the verdict once more was that they were still slaves. The case was then appealed to the U. S. Supreme Court.

Seven of the nine Supreme Court Justices concluded that the Scotts remained slaves. Chief Justice Roger Taney authored the most important opinion for a majority of the Court. Taney first addressed the question of whether the Scotts were citizens and thus entitled to bring suit in a U. S. court. He wrote: “We think they are not, and that they are not included, and were not intended to be included, under the word ‘citizens’ in the Constitution and can, therefore, claim none of the rights and privileges which that instrument provides for and secures to citizens of the United States.” Still writing for a majority of the Court, Taney also wrote: “…it is the opinion of the Court that the Act of Congress (the Missouri Compromise of 1820) which prohibited a citizen from holding and owning property of this kind in the territory of the United States north of the line therein mentioned, is not warranted by the Constitution, and is therefore void.” The Court thus declared the Missouri Compromise unconstitutional and in the process emphasized the importance of protecting property rights, in this case property being slaves.

The first sentence of Section 1 of the Fourteenth Amendment added to the Constitution in 1868 declares that “all persons born or naturalized in the United States and subject to the jurisdiction thereof, are citizens of the United States and of the state wherein they reside.” It was written and added to the Constitution for the specific purpose of overruling the Supreme Court’s decision in Dred Scott v Sanford.