The Supreme Court’s Dred Scott’s decision had a direct impact on the start of the Civil War as well as Abraham Lincoln’s presidency four years later.
At the time of the case of Dred v. Sanford, the Supreme Court’s majority came from pro-slavery states or had connections to pro-slavery presidents.
The Dred Scott decision came just two days after president James Buchanan took office and it set the tone for his controversial term that led to the Civil War. Chief Justice Roger Taney gave the court’s opinion; it had ruled 7-2 against Scott.
Taney announced that slaves were not citizens of the United States and had no rights to sue in federal courts. The court also declared the Missouri Compromise of 1820 unconstitutional; the Congress had no authority to prohibit slavery in the territories.
The decision was well received in the South and by the slavery supporters. The North and the abolitionist didn’t like it. Lincoln, a member of the newly formed Republican Party was not happy following the decision.
The decision made the Republican Party a national force and led to the division of the Democratic Party during the 1860 presidential elections.
The Republican Party received considerable support from the Northern states. This created fears in the south that slavery would be ended. This started the momentum for secession and the Civil War.
After the civil war, the 13th amendment and 14th amendment effectively overturned the Dred Scott decision.
Source: Dred Scott decision still resonates today
National Constitution Center, Constitution Daily