The U.S. Supreme Court case Michigan v. Wisconsin in 1925 was a dispute over the boundary line between the two states, specifically concerning an area of water known as Green Bay and Lake Michigan. The disagreement arose due to differing interpretations of an 1836 treaty with local Native American tribes which had originally defined the boundaries. Wisconsin argued that its border extended into parts of Lake Michigan, while Michigan claimed those areas were within its jurisdiction based on historical precedent and geographical features such as rivers and bays. After examining evidence including maps, treaties, statutes, and other historical documents from both sides, the Supreme Court ruled in favor of Michigan's interpretation by confirming that it held jurisdiction over all waters up to a line drawn eastward from where Menominee River enters Green Bay.

In the dissenting opinion for Michigan v. Wisconsin, 1925, it was argued that the court should not have jurisdiction over this case as it involves a dispute between states about their boundaries. The dissenting justices believed that such matters should be resolved through negotiation and agreement between the states involved rather than by judicial decision. They also expressed concern about setting a precedent where any state could bring another to court over boundary disputes instead of resolving these issues diplomatically or legislatively. Furthermore, they disagreed with how the majority interpreted historical documents and treaties in determining the boundary line, arguing that these sources were ambiguous and open to different interpretations.