In the case of Nebraska v. Iowa in 1891, the U.S. Supreme Court was tasked with settling a border dispute between the two states. The disagreement arose due to changes in the course of Missouri River, which served as a boundary line between them. Nebraska claimed that despite shifts in river's course over time, its original channel should still be recognized as their shared border while Iowa argued that new channels created by river movement established this boundary instead. The court ruled in favor of Iowa based on common law principles and historical precedents indicating that when rivers serving as boundaries change gradually through natural processes (avulsion), new boundaries are formed along these altered courses rather than adhering to old ones no longer followed by water flow.

In the dissenting opinion for Nebraska v. Iowa, 1891, it was argued that the majority's decision to uphold a previous boundary line between Nebraska and Iowa was incorrect due to changes in the course of Missouri River over time. The dissenters believed that these natural alterations should be taken into account when determining state boundaries as they significantly impact land ownership and jurisdictional authority. They contended that by ignoring such changes, the court failed to adhere to established principles of international law which dictate that borders shift along with navigable rivers. Therefore, they disagreed with affirming an outdated border line based on historical surveys rather than current geographical realities.