United Mine Workers of America v. Gibbs
The Supreme Court of the United States held that in order for a United States district court to have pendent jurisdiction over a state-law cause of action, state and federal claims must arise from the same "common nucleus of operative fact" and the plaintiff must expect to try them all at once.
383 U.S. 715 · No. 243 · 1965 term · Warren Court
Decided Mar 28, 1966 · argued Jan 20, 1966
Judicial power · Judicial administration: ancillary or pendent jurisdiction
Majority opinion: William Brennan
The voteMajority
8–08 in the majority, 0 in dissent
No dissent (9–0)
Reversed. United Mine Workers of America won.
What this ruling means
Reversed: the Supreme Court overturned the decision of the U.S. Court of Appeals, Sixth Circuit, and its own ruling ends the case.
United Mine Workers of America was the petitioner, the side that asked the Supreme Court to review the case. “Won” means the Court gave that side the result it asked for.
From the Supreme Court Database. A justice who agreed with the result but not the reasoning counts in the majority.
Summary
The opening of the case’s Wikipedia article: what the case was about and what the Court held.
United Mine Workers of America v. Gibbs, 383 U.S. 715 (1966), was a case in which the Supreme Court of the United States held that in order for a United States district court to have pendent jurisdiction over a state-law cause of action, state and federal claims must arise from the same "common nucleus of operative fact" and the plaintiff must expect to try them all at once. This case was decided before the existence of the current supplemental jurisdiction statute, 28 U.S.C. § 1367.
Data notes
The text is Wikipedia’s (CC BY-SA 4.0), matched to the case by its citation, docket number or name and year, and is not checked against the opinion. The site keeps the article’s opening section, ending on its last full sentence. The one-sentence summary under the title is the Decisions list’s: Wikipedia’s own ruling sentence, or, tagged “AI-written”, one Claude wrote from this opening.
How the justices voted
Each justice who took part, placed by their Martin–Quinn ideology score for the 1965 term. Filled: the 8 in the majority. Hollow: the 0 in dissent. Colour is the party of the president who appointed them.
Majority(8)
William BrennanWrote the majority opinion
John HarlanWrote a concurrence
William DouglasJoined the majority
Abe FortasJoined the majority
Hugo BlackJoined the majority
Byron WhiteJoined the majority
Tom ClarkJoined the majority
Potter StewartJoined the majority
Dissent(0)
- None.
Did not take part: Earl Warren.
Data notes
Each justice’s vote and what they wrote are from the justice-centered file of the Supreme Court Database. “Wrote a concurrence” means the justice sided with the majority and wrote separately; a justice who dissented in part is counted on the side they took overall. A justice who wrote nothing is listed as joining their side.
Positions are each justice’s Martin–Quinn score for the case’s term, the same scores as the Ideology page: negative is more liberal, positive more conservative. A score sums up a justice’s votes across the whole term, so it says where they usually sit, not why they voted as they did here. The median line is the Court’s median justice that term.
The parties
Who brought the case to the Court, who answered it, and how it got there.
- Petitioner
- United Mine Workers of AmericaUnion, labor organization, or official
- Respondent
- GibbsManagement, executive officer, or director, of business entity
- Reached the Court by
- Certiorari (the Court chose to hear it)
Data notes
The names are the two sides of the case’s title. The description under each is the Supreme Court Database’s category for that party, in its own wording. The petitioner is the side that asked the Supreme Court to review the decision below. “Why it was taken” appears only when the majority opinion says lower courts disagreed or were unsure about the question; reasons that would fit any case (“to resolve the question presented”, “an important question”) are left out.
The law at issue
The law the Court was asked to apply, and the kind of power it used to decide.
- Decided by
- Supreme Court supervision of lower federal or state courts or original jurisdiction
Data notes
The Supreme Court Database codes the main constitutional provision, statute or court rule each case turned on, and the basis of the decision: judicial review of a federal or state law, interpreting a statute, supervising the lower courts, and so on. A case can rest on more than one. “Overruled” counts only where the majority opinion says so.
Timeline
What happened at the Court and how the case got there, newest first.
- Mar 28, 1966DecidedDecided · Decided 8–0: reversed. United Mine Workers of America won.
- Jan 20, 1966ArguedArgued · Oral argument before the Court.
- Not datedTaken upTaken up · The Supreme Court agreed to hear the case (certiorari).
- Not datedCourt belowCourt below · Decided by the U.S. Court of Appeals, Sixth Circuit: affirmed.
- Not datedBeganBegan · The case began in the Tennessee Eastern U.S. District Court.
Data notes
From the Supreme Court Database: the court the case began in, the court whose decision the Supreme Court reviewed and what that court did, how the case came to the Court, and the dates of argument and decision. The database does not date the steps in the lower courts. Court names are the database’s.
Other decisions on the same issue
5 other argued cases since 1946 on judicial administration: ancillary or pendent jurisdiction, newest first.
- Exxon Mobil Corporation v. Allapattah Services, Inc., et al.545 U.S. 546Jun 23, 2005 · 545 U.S. 546Judicial power5–45–4 band
- Lance Raygor and James Goodchild v. Regents of the University of Minnesota, et al.534 U.S. 533Feb 27, 2002 · 534 U.S. 533Judicial power6–36–3 band
- City of Chicago, et al. v. International College of Surgeons et al.522 U.S. 156Dec 15, 1997 · 522 U.S. 156Judicial power7–27–2 band
- Owen Equipment & Erection Co. v. Kroger, Administratrix437 U.S. 365Jun 21, 1978 · 437 U.S. 365Judicial power7–27–2 band
- Aldinger v. Howard, Treasurer of Spokane County, et al.427 U.S. 1Jun 24, 1976 · 427 U.S. 1Judicial power6–36–3 band
Data notes
Every other orally argued case with a clear vote, from the 1946 term on, that the Supreme Court Database files under the same issue as this one. The database gives each case one issue from a list of about 270 (abortion, search and seizure of vehicles, the death penalty, and so on), whatever law it turned on.
Official record
Read the full opinion on Justia, the argument audio on Oyez and Wikipedia. Case data from the Supreme Court Database, Version 2026 Release 01, through the 2025 term.