|Wisconsin v. Michigan|
|Argued March 2, 1936|
Decided March 16, 1936
|Full case name||The State of Wisconsin v. The State of Michigan|
|Citations||297 U.S. 547 (more)|
56 S. Ct. 584; 80 L. Ed. 856
|Prior||295 U.S. 455 (1935).|
|The boundary between Michigan and Wisconsin is amended as stated|
|Total islands||4: Detroit, Plum, Rock & Washington|
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.
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.