In Scott v. Negro London, the Supreme Court of the United States heard a case concerning slavery and freedom in America. The plaintiff, James Scott, was an African-American man who had been enslaved by his master for many years before running away to Pennsylvania where he lived as a free man for several years. His former master then sued him in Virginia court claiming that he was still legally bound to him as a slave despite living freely in another state. The Supreme Court ultimately ruled against Scott's former master and held that no person could be forced into involuntary servitude unless they were convicted of a crime or otherwise lawfully punished according to law. This decision established important precedent protecting individuals from being deprived of their liberty without due process of law and helped pave the way for future civil rights cases involving slavery and other forms of discrimination throughout American history.

In Scott v. Negro London, Chief Justice Marshall delivered a dissenting opinion in which he argued that the freedom of an enslaved person should not be determined by their residence within a state or territory. He noted that slavery was inconsistent with the principles of natural justice and could only exist as a result of positive law. Furthermore, he stated that if Congress had intended to extend its power over slavery into territories it would have done so explicitly through legislation rather than relying on implication from other laws such as those concerning taxation and representation in Congress. In conclusion, Chief Justice Marshall asserted that since there was no clear indication from Congress regarding whether or not slavery existed in territories then any decision about an individual's status must rest solely upon local law and custom.