Dred Scott was a Missouri slave who had lived for a period in a free state and a free territory and sued for his freedom based on that fact. Scott's case was first filed in the 1840s in Missouri, where he was living at the time, and his fight for freedom eventually ended up in the United States Supreme Court.
On March 6, 1857, the Supreme Court issued one of the most infamous decisions in the history of African Americans and the courts. In the majority opinion, written by Chief Justice Roger B. Taney, the court ruled, first, that African Americans were not citizens of the United States and, therefore, had no right to sue in a U.S. court and, second, that the Missouri Compromise of 1820 was unconstitutional with regard to its prohibition on slavery in part of the Louisiana Purchase Territory. According to Taney, blacks, whether free or slave, could "claim none of the rights and privileges which that instrument [Constitution] provides for and secures to citizens of the United States." In addition, Taney's opinion held that because slaves were property, their owners could not be deprived of their property without due process and struck down the legislation that had prohibited slavery north of the 36 30' parallel line, arguing that Congress had no right to ban slavery in the territories.
The Dred Scott decision further widened the divisions in the United States over the issue of slavery. The decision figured in the Lincoln-Douglas debates in the U.S. Senate race in Illinois the following year, with Lincoln expressing the belief that the court's opinion was a step toward nationalizing slavery.
