United Mine Workers v. Gibbs 383 U.S. 715, 86 S.Ct. 1130, 16 L.Ed. 2d. 218 (1966) Gibbs was hired as a mine superintendent by Grundy Corp., a wholly-owned subsidiary of Tennessee Consolidated Coal Co. As part of the arrangement, Grundy also gave Gibbs an independent contract to haul coal. The United Mine Workers (UMW) were in conflict with the Southern Labor Union. They forcibly prevented the opening of the mine Gibbs was to be in charge of. Several people were beaten. Gibbs lost his job as a mine superintendent. He also lost the opportunity to haul coal. He lost other contracts and suspected that the UMW was plotting against him. He sued the International UMW (as opposed to the local branch) for violations of the Labor Management Relations Act (LMRA). He also asserted State law claims for conspiracy. Since LMRA was a Federal Statute, Gibbs brought the claim in Federal Court. Although the conspiracy charge was a State law claim, Gibbs was able to add it to the Federal Court claim under the doctrine of pendent jurisdiction (aka Rule 18(a)). The doctrine of pendent jurisdiction says that Federal Courts have discretion to hear pendent State claims where there is a substantial Federal claim arising out of a common nucleus of operative fact. Since there was no diversity jurisdiction or anything like that, Gibbs would not have been able to sue UMW in Federal Court if he was only alleging the State claim. In order to qualify for pendant jurisdiction the case has to come out of the same set of operative facts. The Federal Trial Court found for Gibbs and awarded $174k in damages. UMW appealed. The Federal Trial Court found that the UMW had violated the State conspiracy laws. The Court found that Gibbs had no standing to sue under the LMRA, so that part of the case was dismissed. However, the Court found that Gibbs had a winning case based on his State conspiracy claim. UMW argued that since the Federal claim was thrown out, the Federal Court had no jurisdiction to decide a case that was solely a State claim. The Federal Appellate Court affirmed. UMW appealed. The US Supreme Court reversed (but only on the merits). The US Supreme Court found that Federal courts can heard State law claims if they form a separate but parallel ground for relief also sought in a substantial claim based on Federal law. Gibbs was arguing that two laws (a Federal and a State) were broken based on the same set of facts. It would be most efficient to try them both in one judicial proceeding, So, assuming Gibbs had a reasonable Federal claim, the Federal Court can decide to hear the entire case. The Court found that if it appears that the a State claim is the real body of a case, and the Federal claim was only tacked on to get into Federal court, the Federal court can dismiss the State claim and send the case back to State court. It's the Federal court's choice though, they can decide if they want to hear the case or not. The Court reversed the Federal Appellate Court and threw out the State claim on the merits of the case. They agreed that the Federal Courts all had jurisdiction, they just didn't think Gibbs proved his case. Basically, this case is saying that as long as you have a legitimate Federal claim, you can sue in a Federal court and bring a State claim along with you. If the Federal claim gets dismissed, the Federal court can dismiss the State claim and allow you to go to a State court, or they can continue to hear the State claim. It's the Federal court judge's choice. Pendent jurisdiction (aka supplemental jurisdiction) can allow a Federal court to hear a claim even though there is no diversity jurisdiction or Federal question jurisdiction. See 28 U.S.C. § 1367(a).