McCulloch v. Maryland

In 1818, Maryland imposed a tax on any bank operating within its borders not chartered by the state — a law aimed squarely at the Second Bank of the United States. James McCulloch, the Baltimore branch cashier, refused to pay. Maryland took him to court, and the case climbed to the Supreme Court, where Chief Justice John Marshall turned what began as a tax dispute into one of the most consequential constitutional rulings in American history.

Marshall's unanimous opinion answered two questions shadowing the young republic. First, did Congress have the authority to charter a national bank? The Constitution never says so explicitly, but Marshall found the power implied in the necessary and proper clause — Congress could use any reasonable means to carry out its enumerated powers. Second, could a state tax a federal institution? Absolutely not: "the power to tax involves the power to destroy," Marshall wrote, and a state cannot destroy what the federal government has constitutional authority to create.

McCulloch v. Maryland set the template for how Americans have read the Constitution ever since — as a document whose silences are not prohibitions, but invitations. The doctrine of implied powers made a continental nation possible. Without it, every new federal agency, program, or instrument would need its own constitutional amendment to justify its existence.