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 path over time, original boundaries should be maintained while Iowa argued that borders moved along with river’s alterations. The court ruled in favor of Iowa stating that when rivers serving as state boundaries change their courses gradually through natural means (a process known as avulsion), then political boundaries shift accordingly and do not remain fixed at their original location where they were set when states were admitted into Union or defined by Congress earlier on.

In the dissenting opinion for Nebraska v. Iowa, 1891, it was argued that the majority's decision to uphold a boundary line between Nebraska and Iowa established by an 1851 survey was incorrect. The dissenting justices believed that this ruling ignored historical facts and evidence of long-standing acceptance of a different boundary line by both states. They contended that the Missouri River had naturally shifted its course over time due to erosion and accretion processes, which should have resulted in changes to the state boundaries as well. By adhering strictly to an outdated survey instead of recognizing these natural geographical changes, they felt that the court was disregarding precedent set in previous cases involving similar issues with river boundaries between states. Furthermore, they expressed concern about potential negative impacts on landowners who would suddenly find themselves living in a different state due to this ruling.