A constitution is framed for ages to come, and is designed to approach immortality as nearly as human institutions can approach it. - John Marshall

It has been said, that the people had already surrendered all their powers to the State sovereignties, and had nothing more to give. But, surely, the question whether they may resume and modify the powers granted to government does not remain to be settled in this country. Much more might the legitimacy of the general government be doubted, had it been created by the States. The powers delegated to the State sovereignties were to be exercised by themselves, not by a distinct and independent sovereignty, created by themselves. To the formation of a league, such as was the confederation, the State sovereignties were certainly competent. But when, "in order to form a more perfect union," it was deemed necessary to change this alliance into an effective government, possessing great and sovereign powers, and acting directly on the people, the necessity of 'referring it to the people, and of deriving its powers directly from them, was felt and acknowledged by all.

[T]he constitution controls any legislative act repugnant to it. . . . It is emphatically the province and duty of the judicial department to say what the law is. . . . So if a law be in opposition to the constitution; if both the law and the constitution apply to a particular case, so that the court must either decide that case conformably to the law, disregarding the constitution; or conformably to the constitution disregarding the law; the court must determine which of these conflicting rules governs the case. This is the very essence of judicial duty. . . . Those then who controvert the principle that the constitution is to be considered, in court, as a paramount law, are reduced to the necessity of maintaining that courts must close their eyes on the constitution, and see only the law. This doctrine would subvert the very foundation of all written constitutions . . . It would be giving the legislature a practical and real omnipotence . . . The judicial power of the United States is extended to all cases arising under the constitution.

The Court has bestowed on this subject its most deliberate consideration. The result is a conviction that the States have no power, by taxation or otherwise, to retard, impede, burden, or in any manner control the operations of the constitutional laws enacted by Congress to carry into execution the powers vested in the General Government. This is, we think, the unavoidable consequence of that supremacy which the Constitution has declared. We are unanimously of opinion that the law passed by the Legislature of Maryland, imposing a tax on the Bank of the United States is unconstitutional and void.