Article 6, Clause 2
United States v. Schooner Peggy1 Cranch 103 1801
The Chief Justice [Marshall] delivered the opinion of the court.
. . . . .
The constitution of the United States declares a treaty to be the supreme law of the land. Of consequence, its obligation on the courts of the United States must be admitted. It is certainly true that the execution of a contract between nations is to be demanded from, and, in the general, superintended by the executive of each nation; and, therefore, whatever the decision of this court may be relative to the rights of parties litigating before it, the claim upon the nation, if unsatisfied, may still be asserted. But yet where a treaty is the law of the land, and as such affects the rights of parties litigating in court, that treaty as much binds those rights, and is as much to be regarded by the court, as an act of congress; and although restoration may be an executive, when viewed as a substantive act, independent of, and unconnected with, other circumstances, yet to condemn a vessel, the restoration of which is directed by a law of the land, would be a direct infraction of that law, and, of consequence, improper.
It is in the general truth that the province of an appellate court is only to inquire whether a judgment, when rendered, was erroneous or not. But if subsequent to the judgment and before the decision of the appellate court a law intervenes and positively changes the rule which governs, the law must be obeyed, or its obligation denied. If the law be constitutional, and of that no doubt in the present case has been expressed, I know of no court which can contest its obligation. It is true that in mere private cases between individuals, a court will and ought to struggle hard against a construction which will, by a retrospective operation, affect the rights of parties, but in great national concerns where individual rights, acquired by war, are sacrificed for national purposes, the contract making the sacrifice ought always to receive a construction conforming to its manifest import; and if the nation has given up the vested rights of its citizens, it is not for the court but for the government to consider whether it be a case proper for compensation. In such a case the court must decide according to existing laws, and if it be necessary to set aside a judgment rightful, when rendered, but which cannot be affirmed but in violation of law, the judgment must be set aside.
The Founders' Constitution
Volume 4, Article 6, Clause 2, Document 27
The University of Chicago Press
Easy to print version.