If this is a multiple-choice question, let's eliminate two possibilities immediately - I believe there has been no Supreme Court decision ever to cause slave settlements to be created. The Dred Scott decision settled the other two choices, at least for the time being, and was controversial for several reasons. It basically answered the question: "What happens to the status of slaves when they travel through states where slavery is prohibited?" A related question was: "What happens to the "free" status of former slaves, having been granted freedom in a free state, when they later return to the state where they previously were slaves?" So the decision was all about the status of slaves & former slaves.
After some interesting & amazing preliminary decisions, such as whether the federal court had jurisdiction of the case & whether the plaintiff had standing to bring the case at all, the court apparently found it appropriate enough to offer opinions & even to declare an act of congress unconstitutional.
In the end, the court ruled that descendants of African slaves - even if emancipated - could not be citizens of a state, had no legal standing to sue in federal court, and property of U.S. citizens remained their property (i.e. slaves) regardless of where they might travel.