diversity of citizenship:
1. A basis for federal-court jurisdiction that exists when
(1) a case is between citizens of different states, or between a citizen of a state and an alien, and
(2) the matter in controversy exceeds a specific value (now $75,000). 28 USCA § 1332.
or purposes of diversity jurisdiction, a corporation is considered a citizen of both the state of incorporation and the state of its principal place of business. An unincorporated association, such as a partnership, is considered a citizen of each state where at least one of its members is a citizen. — Often shortened to diversity. See diversity jurisdiction under JURISDICTION. 
1. A ground for invoking the original jurisdiction of a Federal District Court, the basis of jurisdiction on such ground being the existence of an actual and substantial controversy between citizens of different states. There is a diversity of citizenship, in a case involving a plurality of parties, where all the parties on one side of a controversy are citizens of different states from all those on the other side. Indianapolis v Chase Nat. Bank, 314 US 63, 86 L Ed 569, 62 S Ct 355.
The same principle applies in determining diversity of citizenship for the purpose of removing a case from a state court to a federal court. Gainesville v Brown-Crummer Invest. Co. 277 US 54, 72 L Ed 781, 48 S Ct 454. 
1. In a multiparty case, diversity between both sides to the lawsuit so that all plaintiffs have different citizenship from all defendants. * Complete diversity must exist for a federal court to have diversity jurisdiction over the matter. The rule of complete diversity was first laid down by Chief Justice Marshall in Strawbridge v. Curtiss, 7 U.S. (3 Cranch) 267 (1806).
1. Improper or collusively created diversity of citizenship for the sole or primary purpose of creating federal jurisdiction. * Manufactured diversity is prohibited by 28 USCA § 1359.
Diversity of Citizenship Clause:
1. Constitutional law. U.S. Const. art. 111, § 2, cl. 1, giving the federal judiciary power to hear cases between citizens of different states or between a state and a citizen of a different state. * Congress has passed two laws limiting the federal courts’ power: the diversity statute (28 USCA § 1332) and the removal statute (28 USCA § 1441).