A more thorough explanation:

Martin v. Hunter’s Lessee (1816) is a landmark Supreme Court case that established the Supreme Court’s authority over state courts in matters of federal law.

The case involved a land dispute between Martin and Hunter’s Lessee, which was initially decided in favor of Hunter’s Lessee by the Virginia Court of Appeals. However, the Supreme Court of the United States reversed this decision, which the Virginia State court rejected, stating that Section 25 of the Judiciary Act was unconstitutional.

The Supreme Court reconsidered the case and upheld the Judiciary Act, stating that questions of federal law were within the Supreme Court’s jurisdiction. The Court emphasized the importance of having a single, coherent interpretation of the Constitution and federal laws rather than multiple competing interpretations from various state courts.

This case established the Supreme Court’s supremacy in matters of constitutional interpretation and over state courts, making it the most powerful court in the United States.

For example, if a state court makes a decision that conflicts with federal law, the Supreme Court has the authority to overrule that decision and enforce federal law.