In a seven to two decision, the Supreme Court sided against Dred Scott and declared that he was to remain enslaved. Somewhat dodging the issue of whether or not spending time in a free state gave an enslaved person their freedom, Chief Justice Roger Taney wrote in his opinion that Scott did not even have the right to bring his case to court because enslaved people were not citizens. Taney went on to say that even free Black people had no legal grounds to bring a suit since they were not considered full citizens. In short, Taney ruled that Black people "had no rights which the White man was bound to respect".

At the time of the Dred Scott case, there were no federal laws concerning what would become of an enslaved person who was moved from a slave state to a free state and then back to a slave state. Taney and the other justices in the majority opinion, essentially said that Black people, no matter their free or enslaved status, had no access to the legal system. The decision cemented Black people as an underclass in the country.

The Court also ruled that Congress and territorial governments had no power to ban or limit slavery. In effect, this ruling nullified the Missouri Compromise of 1820, which drew a line on the map of where slavery would be permitted and outlawed, and heightened tensions that would eventually boil over into the Civil War.