In McCulloch vs. Maryland, the supremacy clause when reinforced when the court deemed that Maryland could not tax a branch of the national bank in their state. It was also the first use of the Necessary and Proper Clause because the national bank is not an enumerated power.
In Gibbons vs. Ogden, the national government was given the power to regulate interstate commerce.
In Lopez vs. US, the supreme court fought back against the national government, which was not able to regulate weapon possession because it is not a commerce issue. We discussed whether or not we agreed with the decision.