In the United States Supreme Court case of The United States v. Domingo and Vicente Peralta, the court was asked to decide whether two brothers had a valid claim to land in California that they inherited from their father. The government argued that since their father did not have legal title to the land when he died, his sons could not inherit it either. However, the brothers claimed that they were entitled to possess and use this property under Spanish law which allowed them rights as occupants of public lands prior to American occupation. After considering both sides' arguments, the court ultimately ruled in favor of Domingo and Vicente Peralta by holding that Spanish laws applied at least until such time as Congress passed legislation on how these claims should be handled. This decision established an important precedent for future cases involving similar issues concerning ownership of public lands in California during its transition from Mexican rule into American control.

In the case of The United States v. Domingo and Vicente Peralta, the Supreme Court was tasked with determining whether or not a Mexican land grant issued to Domingo and Vicente Peralta in 1841 by the Mexican government was valid under U.S. law after California became part of the United States following its admission as a state in 1850. In an opinion delivered by Justice Curtis, it was held that while Congress had authority to determine what laws would be applicable within newly acquired territories such as California, they did not have power to invalidate existing grants made prior to acquisition unless there were clear indications that those grants were fraudulent or otherwise illegal under Mexican law at the time they were issued. As no evidence existed indicating any illegality on behalf of either party involved in this particular transaction, it could not be overturned simply because it occurred before California's annexation into the Union; thus, both parties retained their rights over said property according to their original agreement from 1841 and subsequent confirmation from Mexico's government shortly thereafter.