| Litigants: | National Mutual Insurance Company v. Tidewater Transfer Company |
| Arguedate: | November 8 |
| Argueyear: | 1948 |
| Decidedate: | June 20 |
| Decideyear: | 1949 |
| Fullname: | National Mutual Insurance Company v. Tidewater Transfer Company |
| Usvol: | 337 |
| Uspage: | 582 |
| Parallelcitations: | 69 S. Ct. 1173; 93 L. Ed. 1556; 1949 U.S. LEXIS 2924 |
| Holding: | , treating citizens of United States territories as citizens of a state for the purpose of establishing diversity jurisdiction, is constitutional. |
| Plurality: | Jackson |
| Joinplurality: | Black, Burton |
| Concurrence: | Rutledge |
| Joinconcurrence: | Murphy |
| Dissent: | Vinson |
| Joindissent: | Douglas |
| Dissent2: | Frankfurter |
| Joindissent2: | Reed |
National Mutual Insurance Company v. Tidewater Transfer Company, 337 U.S. 582 (1949), was a United States Supreme Court case that upheld the constitutionality of 28 U.S.C. §1332(e). §1332(e) treats citizens of United States territories as citizens of a state for the purpose of establishing diversity jurisdiction.[1]