Of course, in defense of Supreme Court justices, they were just interpreting what the US Constitution said at the time, that an African Americans was three-fifths of a person, as decided in the Compromise of 1787. It took the Thirteenth Amendment to the Constitution, enacted in 1865, to abolish slavery and eliminate the three-fifths clause from the Constitution. The nation’s founders kept kicking the can down the road, avoiding the hard issues of slavery until civil war was inevitable, and avoiding the hard issues of segregation and racial equality, until the civil rights movement forced the nation to confront the issue.
“Congress almost banned slavery in new US territories in 1784. It only failed by one vote. That means slavery would have only been legal in the original slave states, from GA up to MD. As soon as a single other free state joined, slavery could have been banned.” — Historian Al Carroll.
The Dred Scott decision was written by Roger Taney, one of the court’s worst justices.