In the case of The United States v. Joseph Reynes, the Supreme Court was asked to decide whether a Mexican citizen who had been living in California since 1845 could be convicted for violating an act of Congress that prohibited citizens from trading with Native Americans without permission from the government. The court held that Reynes was not subject to prosecution under this law because he did not owe allegiance to any sovereign power and thus could not be considered a “citizen” as defined by U.S. law at the time. Furthermore, it found that even if he were considered a citizen, his actions would still have been permissible due to their location within Mexico's borders prior to its cession in 1848 and therefore outside of U.S jurisdiction at the time they occurred. This decision established important precedent regarding citizenship rights and limitations on federal authority over foreign nationals residing within its boundaries

In the case of The United States v. Joseph Reynes, the Supreme Court was asked to decide whether a Mexican citizen who had been living in California since 1846 could be convicted for selling liquor without a license. Justice McLean delivered an opinion dissenting from that of the majority, arguing that as a Mexican citizen and resident of California prior to its admission into the Union, Reynes should not have been subject to prosecution under federal law. He argued that while Congress has power over territories acquired by treaty or conquest, it does not extend beyond those limits; thus any laws passed after California's admission were only applicable within her boundaries and did not apply retroactively to persons residing there before statehood. Furthermore, he noted that even if such laws applied retrospectively they would still be unconstitutional because they violated Article IV Section 2 Clause 1 which states "the citizens of each State shall be entitled to all privileges and immunities" regardless of their place or date of residence. Therefore he concluded that Reynes' conviction should have been overturned on appeal due his status as a pre-statehood resident in good standing with Mexico at the time when he committed his alleged offense