Wisconsin v. Michigan

Two Supreme Court cases, Wisconsin v. Michigan, 295 U.S. 455 (1935) and Wisconsin v. Michigan, 297 U.S. 547 (1936), settled a territorial dispute between Wisconsin and Michigan.

Wisconsin v. Michigan
Seal of the United States Supreme Court
Argued March 2, 1936
Decided March 16, 1936
Full case nameThe State of Wisconsin v. The State of Michigan
Citations297 U.S. 547 (more)
56 S. Ct. 584; 80 L. Ed. 856
Case history
Prior295 U.S. 455 (1935).
The boundary between Michigan and Wisconsin is amended as stated
Court membership
Chief Justice
Charles E. Hughes
Associate Justices
Willis Van Devanter · James C. McReynolds
Louis Brandeis · George Sutherland
Pierce Butler · Harlan F. Stone
Owen Roberts · Benjamin N. Cardozo
Case opinion
Disputed area
Disputed area is located in Wisconsin
Disputed area
Disputed area
Ships passing between Green Bay (left) and Lake Michigan (right) traveled between various islands.
Disputed area is located in the United States
Disputed area
Disputed area
Disputed area (the United States)
Coordinates45°19′17″N 86°54′58″W / 45.321487°N 86.916073°W / 45.321487; -86.916073Coordinates: 45°19′17″N 86°54′58″W / 45.321487°N 86.916073°W / 45.321487; -86.916073
Total islands4: Detroit, Plum, Rock & Washington


The 1836 boundary description between Wisconsin and Michigan described the line through northwest Lake Michigan as "the most usual ship channel". This description needed clarification as two routes were in use into Green Bay. Four islands lay in between and all were claimed as part of both Door County, Wisconsin, and Delta County, Michigan. A similar case, Michigan v. Wisconsin 270 U.S. 295 (1926), had previously been brought to the Supreme Court but was dismissed.


In 1936, the Supreme Court decision chose the northernmost ship channel as the more common, so Michigan lost the intervening water area and four islands: Plum, Detroit, Washington, and Rock.

See alsoEdit

  • Toledo War: a border dispute between Michigan and Ohio


  • "The Evolution of Michigan's Legal Boundary". Michigan State University Map Library. Retrieved September 28, 2008.
  • Kellogg, Louise P. (1917). "The Disputed Michigan–Wisconsin Boundary". Wisconsin Magazine of History. Retrieved September 28, 2008.
  • Rohde, William C. "Wisconsin–Upper Michigan State Boundary Surveys". Wisconsin Society of Land Surveyors. Retrieved September 29, 2008.
  • "Surveyor's Tree Blaze: Surveyor's tree blaze from the 1841 expedition to lay out the boundary between Wisconsin and Michigan, found at Trout Lake, Vilas County, Wisconsin". Wisconsin History Magazine. Retrieved September 28, 2008.
  • Captain Cram's reports were printed in: Message from the President of the United States, in compliance with a resolution from the Senate in relation to the survey to ascertain and designate the boundary-line between the state of Michigan and the territory of Wiskonsin. Washington, DC: Blair & Rives, Printers. 1841. Senate Document no. 151, 26th Congress, 2d session.
  • United States Army Corps of Topographical Engineers (1842). Report of the Secretary of War: communicating, in compliance with a resolution of the Senate, a copy of the report of the survey of the boundary between the state of Michigan and the territory of Wisconsin. Washington, DC: Thomas Allen, Printers. Senate Document no. 170, 27th Congress, 2d session.
  • Martin, Lawrence (September 1930). "The Michigan–Wisconsin Boundary Case in the Supreme Court of the United States, 1923–26". Annals of the Association of American Geographers. Vol. 20 no. 3. pp. 106–163.

External linksEdit