In which case did the Supreme Court rule that state law can be overridden by federal law?

McCulloch v. Maryland is significant because it established the principle that federal law takes precedence over state law when the two conflict. In this landmark case, the Supreme Court ruled that the state of Maryland could not tax the Second Bank of the United States, asserting that the federal government had implied powers to create a bank under the Necessary and Proper Clause of the U.S. Constitution. This ruling reinforced the supremacy of federal authority in instances where state law attempts to interfere with or undermine federal operations, thereby creating a strong foundation for federal power over states in the context of constitutional governance. The decision highlighted the importance of the federal government’s ability to operate without undue interference from state governments, ensuring a unified legal framework across the nation.