The term "Dred Scott Decision" refers to the 1857 Supreme Court case Dred Scott v. Sandford, which had profound implications for the legal status of enslaved individuals and the issue of slavery in the United States. Dred Scott, an enslaved man, sued for his freedom after living in free territories. The Court ruled against him, stating that individuals of African descent were not U.S. citizens and had no right to sue. Additionally, the decision declared the Missouri Compromise unconstitutional, asserting that Congress could not prohibit slavery in the territories. This ruling intensified national divisions over slavery and contributed to the tensions leading up to the Civil War.