The Dred Scott decision contributed significantly to the lead-up to the Civil War. Issued by the Supreme Court in 1857, the ruling stated that African Americans, whether free or enslaved, could not be American citizens and therefore had no standing to sue in federal court. Additionally, the decision invalidated the Missouri Compromise by declaring that Congress had no authority to prohibit slavery in the territories.
While the Dred Scott decision also heightened tensions surrounding abolitionist activities and contributed to conflicts like Bleeding Kansas, its most direct impact was on the national debate over slavery, ultimately exacerbating the divisions between the North and South and contributing to the outbreak of the Civil War.