Baltimore and Potomac Railroad Company v. Hopkins‪.‬

Appellate jurisdiction was conferred on this court by the 25th section of the Judiciary Act of 1789, over final judgments and decrees in any suit in the highest court of law or equity of a State in which a decision in the suit could be had, in three classes of cases: First, where is drawn in question the validity of a treaty or statute of, or an authority exercised under, the United States, and the decision is against their validity; secondly, where is drawn in question the validity of a statute of, or an authority exercised under, any State, on the ground of their bring repugnant to the Constitution, treaties, or laws of the United States, and the decision is in favor of such their validity; thirdly, where is drawn in question the construction of any clause of the Constitution, or of a treaty, or statute of, or commission held under, the United States, and the decision is against the title, right, privilege, or exemption specially set up or claimed by either party, under such clause of the said Constitution, treaty, statute, or commission. 1 Stat. 73, 85, c. 20, ? 25.