List of United States Supreme Court cases, volume 112

This is a list of cases reported in volume 112 of United States Reports, decided by the Supreme Court of the United States in 1884 and 1885.

Justices of the Supreme Court at the time of volume 112 U.S.
The Supreme Court is established by Article III, Section 1 of the Constitution of the United States, which says: "The judicial Power of the United States, shall be vested in one supreme Court . . .". The size of the Court is not specified; the Constitution leaves it to Congress to set the number of justices. Under the Judiciary Act of 1789 Congress originally fixed the number of justices at six (one chief justice and five associate justices). Since 1789 Congress has varied the size of the Court from six to seven, nine, ten, and back to nine justices (always including one chief justice).

When the cases in volume 112 U.S. were decided the Court comprised the following nine members:

Elk v. Wilkins
Elk v. Wilkins, 112 U.S. 94 (1884), is a landmark decision of the Supreme Court respecting the citizenship status of Indians. John Elk, a Winnebago Indian, was born on an Indian reservation and later resided with whites on the non-reservation US territory in Omaha, Nebraska, where he renounced his former tribal allegiance and claimed citizenship by virtue of the Citizenship Clause. The case came about after Elk tried to register to vote in 1880 and was denied by Charles Wilkins, the named defendant, who was registrar of voters of the Fifth ward of the City of Omaha. The Court decided that even though Elk was born in the United States, he was not a citizen because he owed allegiance to his tribe when he was born rather than to the United States and therefore was not subject to the jurisdiction of the United States when he was born.

Head Money Cases
The Head Money Cases, 112 U.S. 580 (1884), relate to the legal status of treaties. Under the Immigration Act of 1882, officers from the customhouse in the Port of New York began collecting a tax from ships of fifty cents for each immigrant aboard. Multiple ship owners sued because they were transporting Dutch immigrants, and the Netherlands had a treaty with the United States that they claimed prohibited the tax. The decision established that treaties, which are described in the Supremacy Clause of the US Constitution as "the supreme law of the land" equal to any domestic federal law, do not hold a privileged position above other acts of Congress. So, other laws affecting the "enforcement, modification, or repeal" of treaties are legitimate.

Citation style
Under the Judiciary Act of 1789 the federal court structure at the time comprised District Courts, which had general trial jurisdiction; Circuit Courts, which had mixed trial and appellate (from the US District Courts) jurisdiction; and the United States Supreme Court, which had appellate jurisdiction over the federal District and Circuit courts—and for certain issues over state courts. The Supreme Court also had limited original jurisdiction (i.e., in which cases could be filed directly with the Supreme Court without first having been heard by a lower federal or state court). There were one or more federal District Courts and/or Circuit Courts in each state, territory, or other geographical region.

Bluebook citation style is used for case names, citations, and jurisdictions.
 * "C.C.D." = United States Circuit Court for the District of . ..
 * e.g.,"C.C.D.N.J." = United States Circuit Court for the District of New Jersey
 * "D." = United States District Court for the District of . ..
 * e.g.,"D. Mass." = United States District Court for the District of Massachusetts
 * "E." = Eastern; "M." = Middle; "N." = Northern; "S." = Southern; "W." = Western
 * e.g.,"C.C.S.D.N.Y." = United States Circuit Court for the Southern District of New York
 * e.g.,"M.D. Ala." = United States District Court for the Middle District of Alabama
 * "Ct. Cl." = United States Court of Claims
 * The abbreviation of a state's name alone indicates the highest appellate court in that state's judiciary at the time.
 * e.g.,"Pa." = Supreme Court of Pennsylvania
 * e.g.,"Me." = Supreme Judicial Court of Maine