What was McCulloch v. Maryland?

McCulloch v. Maryland (1819) was a landmark Supreme Court case that established the principle of federal supremacy over state laws. The case arose when the state of Maryland attempted to tax the Second Bank of the United States, and the bank's cashier, James McCulloch, challenged the tax. The Court, led by Chief Justice John Marshall, ruled that Congress had the authority to create the bank under the Necessary and Proper Clause of the Constitution, and that Maryland could not tax the bank, reinforcing the federal government's power. This decision set a precedent for the expansion of federal authority and the interpretation of the Constitution.