The decision in the case of Dred Scott pronounced the Missouri Compromise (1820) unconstitutional and served to deepen the divide between North and South, helping pave the way for the Civil War (1861–65).

In the mid-1800s Dred Scott (c. 1795–1858), who had been born into slavery in Virginia, tried to claim his freedom on the basis that he had traveled with his owner, a doctor, in Wisconsin and Illinois, where slavery had been prohibited by the Missouri Compromise. By the compromise, Congress decided to admit Missouri as a slavery state and Maine as a free state, and declared that the territories north of the 36th parallel (present-day Missouri’s southern border) were free, with the exception of the state of Missouri.

After a lifetime of slavery, Dred Scott sued Missouri for his freedom in April 1846. The case, which hinged on Scott’s travels in free territories in the North, went through two trials; the second was granted due to a procedural error in the first. In 1850, at the conclusion of the second trial, a Missouri jury ruled Scott a free man based on precedents that indicated residence in a free territory or state resulted in emancipation, regardless of the fact that Missouri itself was a slave state. John F. A. Sanford, the lawyer for Scott’s owner, immediately appealed the decision before the Missouri Supreme Court, where a pro-slavery judge reversed the ruling, rescinding Scott’s freedom.

But the case was not over yet: Because Sanford had filed the court papers under his own name rather than that of Scott’s former owner, the case of Scott v. Sanford (because of a filing error, the case is also rendered as Scott v. Sandford) took an interesting twist. Scott hired a new lawyer who was able to get the case before the federal court: Sanford had moved to New York, and since the appellant (Scott) and the registered defendant (Sanford) were now residents of different states, the case came under federal purview. In 1854 a circuit court in St. Louis again heard Dred Scott’s case, but his freedom was again denied. This decision was appealed to the U.S. Supreme Court, which began hearing the case in 1856.

In March 1857 the Supreme Court, which had a southern majority, ruled that Scott’s residence in Wisconsin and Illinois did not make him free, that a black (a “Negro descended from slaves”) had no rights as an American citizen and therefore could not bring suit in a federal court, and that Congress never had the authority to ban slavery in the territories. Dred Scott died the following year.