437 U.S. 365 (1978)
On January 18, 1972, James Kroger was electrocuted when the boom of a steel crane next to which he was walking came too close to a high-tension electric power line.1 The respondent, his widow and administratrix of his estate, filed a wrongful-death action in the United States District Court for the District of Nebraska against the Omaha Public Power District.2 Her complaint alleged that OPPD's negligent construction, maintenance, and operation of the power line had caused Kroger's death.3 Federal jurisdiction was based on diversity of citizenship, since the respondent was a citizen of Iowa and OPPD was a Nebraska corporation.4
OPPD then filed a third-party complaint pursuant to Fed. Rule Civ. Proc. 14 (a) against the petitioner, Owen Equipment and Erection Co., alleging that the crane was owned and operated by Owen, and that Owen's negligence had been the proximate cause of Kroger's death.5 OPPD later moved for summary judgment on the respondent's complaint against it.6 While this motion was pending, the respondent was granted leave to file an amended complaint naming Owen as an additional defendant.7 Thereafter, the District Court granted OPPD's motion for summary judgment in an unreported opinion.8 The case thus went to trial between the respondent and the petitioner alone.9
The respondent's amended complaint alleged that Owen was a Nebraska corporation with its principal place of business in Nebraska.10 Owen's answer admitted that it was a corporation organized and existing under the laws of the State of Nebraska, and denied every other allegation of the complaint.11 On the third day of trial, however, it was disclosed that the petitioner's principal place of business was in Iowa, not Nebraska, and that the petitioner and the respondent were thus both citizens of Iowa.12 The petitioner then moved to dismiss the complaint for lack of jurisdiction.13 The District Court reserved decision on the motion, and the jury thereafter returned a verdict in favor of the respondent.14 In an unreported opinion issued after the trial, the District Court denied the petitioner's motion to dismiss the complaint.15
The judgment was affirmed on appeal.16 The Court of Appeals for the Eighth Circuit held that the District Court had jurisdictional power, in its discretion, to adjudicate the respondent's claim against the petitioner because that claim arose from the core of operative facts giving rise to both the respondent's claim against OPPD and OPPD's claim against Owen.17 Rehearing en banc was denied by an equally divided court.18 The Supreme Court granted certiorari because this decision conflicts with several recent decisions of other Courts of Appeals.19
Whether in an action in which federal jurisdiction is based on diversity of citizenship, the plaintiff may assert a claim against a third-party defendant when there is no independent basis for federal jurisdiction over that claim?20
28 U.S.C. § 1332(a)(1) confers upon federal courts jurisdiction over civil actions where the matter in controversy exceeds the sum or value of $10,000 and is between citizens of different States.21 This statute and its predecessors have consistently been held to require complete diversity of citizenship.22 That is, diversity jurisdiction does not exist unless each defendant is a citizen of a different State from each plaintiff.23 Although the doctrine of ancillary jurisdiction permits federal courts to hear nonfederal claims in situations involving impleader, cross-claims or counterclaims, the context in which the nonfederal claim is asserted is crucial.24 A plaintiff's claim against a third-party defendant in a diversity case does not qualify because it is a new and independent claim rather than one logically dependent on the original action.25
No. The facts establish that the respondent, a citizen of Iowa, initially brought suit against OPPD, a Nebraska corporation, satisfying the complete diversity requirement under 28 U.S.C. § 1332(a)(1).26
Subsequently, after OPPD impleaded Owen and the respondent amended her complaint to name Owen as a defendant, it was disclosed during trial that Owen's principal place of business was in Iowa. This destroyed complete diversity because both the respondent and Owen were citizens of Iowa.27
The Court of Appeals relied on the common nucleus of operative fact test from Mine Workers v. Gibbs, but that test addresses only the constitutional minimum and does not override the statutory requirement of complete diversity.28 The claim asserted by the plaintiff against the third-party defendant was entirely separate from the original claim and not ancillary in the sense required for jurisdiction without an independent basis.29
The Supreme Court reversed the judgment of the Court of Appeals. It concluded that the District Court lacked jurisdiction over the respondent's claim against the petitioner. There was no independent basis for federal jurisdiction. Ancillary jurisdiction does not extend to such claims in diversity cases.30
Related opinions on this issue
Joined by Mr. Justice Brennan
Justice White dissented from the Court's approach to ancillary jurisdiction in diversity cases.31 He stated that the District Court had constitutional power under Article III to entertain the claim because it derived from a common nucleus of operative fact with the original claim.32 He argued that the complete-diversity requirement should not be read so broadly as to prohibit ancillary jurisdiction over a plaintiff's claim against a third-party defendant already brought into the suit by the defendant.33
Considerations of judicial economy, convenience, and fairness support recognizing such jurisdiction.34 There is no occasion for deliberate circumvention of the diversity requirement absent collusion, which can be addressed under 28 U.S.C. § 1359.35 The majority's approach unnecessarily expands the scope of the complete-diversity requirement while substantially limiting the doctrine of ancillary jurisdiction.36