Final answer:
The decision in McCulloch v. Maryland (1819) was that the federal government has the power to establish a national bank. This case established the doctrine of implied powers and affirmed the principle of national supremacy.
Step-by-step explanation:
The decision in McCulloch v. Maryland (1819) was that the federal government has the power to establish a national bank. Chief Justice John Marshall argued that Congress could create a national bank under the necessary and proper clause of Article I, Section 8. This case established the doctrine of implied powers, granting Congress discretionary power to fulfill its constitutional responsibilities. The decision also affirmed the principle of national supremacy, stating that the Constitution and federal laws trump state laws.