The Dred Scott Decision was a landmark Supreme Court case in 1857 that had significant implications for the African American population in the United States. Dred Scott was an enslaved African American man who had been taken by his owner to live in free states and territories where slavery was prohibited. Scott sought his freedom on the basis of his residence in free territory. However, the Supreme Court, in a 7-2 decision, ruled against him, stating that African Americans, whether free or enslaved, could not be considered citizens of the United States and therefore had no standing to sue in federal court.

The decision also declared that the Missouri Compromise of 1820, which had prohibited slavery in certain territories, was unconstitutional. This decision effectively invalidated the idea that Congress had the power to regulate slavery in the territories and further fueled tensions between the North and the South over the issue of slavery.

The Dred Scott Decision is seen as a dark chapter in American history, further entrenching the institution of slavery and denying basic rights to African Americans. The decision highlighted the deep-seated racism and discrimination that existed in the United States at the time and helped to precipitate the Civil War, which ultimately led to the abolition of slavery.