What is the significance of Marbury v. Madison? McCulloch v. Maryland?
Both are US Supreme Court decisions that expanded government powers beyond the specific wording of the US Constitution.
Marbury v. Madison (1803) was an early Supreme Court case, involving a judicial appointment that John Adams signed on his way out of office and that Thomas Jefferson, his successor, discarded. The appointment was signed by Adams but never delivered, and Jefferson wanted his own appointment for the bench.
The case reached the Supreme Court after two years and the high court took the opportunity to establish itself as the final arbiter of the constitutionality of new laws (a role not specifically mentioned in the Constitution). Within the legal profession, this put precedent on a par with actual legislation. It was widely seen as a naked power grab by the high court,
McCulloch v. Maryland (1819) was initially about the state of Maryland taxing the only out-of-state bank operating within the state's boundaries. The wording of the law allowed Maryland to tax all out-of-state banks operating within it, but only the Second Bank of the United States fit the description.
SCOTUS invoked the Necessary and Proper Clause of the Constitution to allow Congress to block the Maryland law, even though the Constitution did not enumerate that specific power to them. It set a precedent for Congress claiming and exercising powers that the Constitution did not expressly give it.