Interstate Relations cases at the Supreme Court

Cases between states, such as boundary and water disputes, usually heard under the Court's original jurisdiction.

Issues in this area

Number of decisions SCDB assigns to each specific issue. Issues with at least 5 decisions have their own page.

Decisions that altered precedent or struck down a law (2)

• Union National Bank v. LambLaw held unconstitutional
  337 U.S. 38Decided May 16, 19496–3William O. Douglas
• Order of United Commercial Travelers of America v. WolfeLaw held unconstitutional
  331 U.S. 586Decided June 9, 19475–4Harold H. Burton

Most recent decisions

• Texas v. New Mexico and Colorado
  144 S. Ct. 1756Decided June 21, 20245–4Ketanji Brown Jackson
• New York v. New Jersey
  598 U.S. 218Decided April 18, 20239–0Brett M. Kavanaugh
• Delaware v. Pennsylvania and Wisconsin
  598 U.S. 115Decided February 28, 20239–0Ketanji Brown Jackson
• Mississippi v. Tennessee
  142 S. Ct. 31Decided November 21, 20219–0John G. Roberts Jr.
• Florida v. Georgia
  592 U.S. 433Decided April 1, 20219–0Amy Coney Barrett
• Texas v. New Mexico
  141 S. Ct. 509Decided December 14, 20207–1Brett M. Kavanaugh
• Florida v. Georgia
  138 S. Ct. 2502Decided June 27, 20185–4Stephen G. Breyer
• Texas v. New Mexico and Colorado
  138 S. Ct. 954Decided March 5, 20189–0Neil M. Gorsuch
• Montana v. Wyoming
  138 S. Ct. 758Decided February 20, 20188–0
• State of Montana v. State of Wyoming and State of North Dakota
  577 U.S. 423Decided March 21, 20168–0
• Kansas v. Nebraska and Colorado
  574 U.S. 445Decided February 24, 20156–3Elena Kagan
• State of Montana v. State of Wyoming and State of North Dakota
  563 U.S. 368Decided May 2, 20117–1Clarence Thomas
• State of South Carolina v. State of North Carolina
  558 U.S. 256Decided January 20, 20105–4Samuel A. Alito Jr.
• State of Kansas v. State of Colorado
  556 U.S. 98Decided March 9, 20099–0Samuel A. Alito Jr.
• State of New Jersey v. State of Delaware
  552 U.S. 597Decided March 31, 20085–3Ruth Bader Ginsburg
• State of Arizona v. State of California
  547 U.S. 150Decided March 27, 20069–0
• State of Kansas v. State of Colorado
  543 U.S. 86Decided December 7, 20048–1Stephen G. Breyer
• State of Kansas v. States of Nebraska and Colorado
  538 U.S. 720Decided May 19, 20039–0
• Franchise Tax Board of California v. Gilbert P. Hyatt
  538 U.S. 488Decided April 23, 20039–0Sandra Day O'Connor
• State of Nebraska v. States of Wyoming and Colorado
  534 U.S. 40Decided November 13, 20019–0
• State of Kansas v. State of Colorado
  533 U.S. 1Decided June 11, 20016–3John Paul Stevens
• State of New Hampshire v. State of Maine
  532 U.S. 742Decided May 29, 20018–0Ruth Bader Ginsburg
• State of New Jersey v. State of New York
  526 U.S. 589Decided May 17, 19999–0
• State of New Jersey v. State of New York
  523 U.S. 767Decided May 26, 19986–3David H. Souter
• Kenneth Lee Baker and Steven Robert Baker v. General Motors Corporation
  522 U.S. 222Decided January 13, 19989–0Ruth Bader Ginsburg
• State of Louisiana v. State of Mississippi
  516 U.S. 122Decided December 4, 19959–0
• Louisiana v. Mississippi
  516 U.S. 22Decided October 31, 19959–0Anthony M. Kennedy
• State of Nebraska v. States of Wyoming and Colorado
  515 U.S. 1Decided May 30, 19958–1David H. Souter
• State of Kansas v. State of Colorado
  514 U.S. 673Decided May 15, 19959–0William H. Rehnquist
• State of Oklahoma and State of Texas v. New Mexico
  510 U.S. 126Decided December 13, 19939–0

Search all 105 Interstate Relations decisions

Source: Supreme Court Database, 2026 Release 01 (data file dated September 8, 2026). Imported into CaseTrail November 5, 2026. Coverage: decisions from the 1946 through 2025 Terms. Methodology · Report an error