Charles Alexander v. The Mayor and Commonalty of Alexandria was a case heard by the United States Supreme Court in 1809. Charles Alexander, an African-American man from Virginia, sued the city of Alexandria for his freedom after being held as a slave despite having been born free according to Virginia law. He argued that he had been illegally enslaved due to a technicality in which his mother's status as an indentured servant had not yet expired when he was born. The court ruled unanimously in favor of Alexander, finding that since he was legally free at birth under Virginia law, it would be unjust to enslave him based on this technicality and thus ordered his immediate release from slavery. This ruling set precedent for future cases involving similar issues regarding slavery and freedom within the state of Virginia.

In the case of Charles Alexander v. The Mayor and Commonalty of Alexandria, the Supreme Court was asked to decide whether a municipal corporation could be sued in federal court. Chief Justice John Marshall wrote a dissenting opinion arguing that it should not be possible for such an action to take place. He argued that since corporations are creatures of state law, they cannot sue or be sued in federal courts because this would interfere with states' rights and sovereignty over their own laws. Furthermore, he reasoned that allowing suits against municipal corporations would open up too many potential lawsuits which could overwhelm the judicial system and lead to confusion about what types of cases can actually proceed in federal court. Ultimately, Marshall concluded that if Congress wanted citizens to have access to justice through suing municipalities then it should pass legislation explicitly authorizing such actions rather than relying on existing legal precedents which do not provide clear guidance on how these matters should be handled by the judiciary.