An article by the American Bar Association's Journal concluded that the Supreme Court's 1857 Dred Scott decision (along with the 1896 Plessy v. Ferguson decision) was the worst decision ever by the Supreme Court.
What happened in Dred Scott, and why the decision made the Civil War inevitable, is explained in this exceptional short (6:09) video from the Minnesota Historical Society.
The video explains Scott's argument that his residence in Minnesota meant that he was entitled to freedom under the terms of the Northwest Ordinance and Missouri Compromise.
Chief Justice Roger B. Taney's 7-2 two-part decision rejected Scott's claims. In the first part, the Court ruled that Scott had no basis to bring his case because as a person descended from a slave, he was not and could never be a citizen of the United States. In the second part, the Court went further, ruling that Congress never had the power to enact any laws restricting slavery, rendering all prior Congressional slavery compromises (like the Compromise of 1850 and Kansas-Nebraska Acts) unconstitutional.
Prof. VanderVelde gives a succinct explanation of the Court decision's impact: After Dred Scott, legislative compromise on slavery was no longer possible. Instead, "There was no political future short of civil war."
To supplement and extend your lesson on this critical case, here are the best digital primary and secondary print resources to use with your students: