United States v. Alire was a United States Supreme Court case that dealt with the issue of whether a Mexican citizen could be convicted of a crime in the United States. The case involved a Mexican citizen, Jose Alire, who was accused of stealing a horse from a United States citizen in California. Alire was arrested and charged with the crime, but he argued that he could not be convicted because he was a Mexican citizen and not a United States citizen. The Supreme Court ultimately ruled in favor of the United States, finding that Alire could be convicted of the crime. The Court reasoned that the United States had jurisdiction over the crime because it had occurred in the United States, and that Alire was subject to the laws of the United States regardless of his citizenship. The Court also noted that the United States had a duty to protect its citizens from crime, and that Alire's citizenship status did not exempt him from this duty. The decision in United States v. Alire established that foreign citizens can be held accountable for crimes committed in the United States, regardless of their citizenship status. This ruling has been cited in numerous cases since then, and it remains an important precedent in the area of criminal law.

In United States v. Alire, the Supreme Court was asked to decide whether a Mexican citizen who had been living in California since 1848 could be convicted of violating an act of Congress that prohibited citizens from selling liquor to Native Americans without a license. The majority opinion held that Alire was not subject to the law because he was not a citizen at the time it passed and therefore did not have any obligation under it. However, Justice Field dissented on this point and argued that although Alire may not have been a citizen when the law passed, he should still be considered bound by its provisions due to his long-term residence in California and his acceptance of its laws as binding upon him. He further argued that if noncitizens were allowed to violate federal laws with impunity simply because they were noncitizens at the time those laws were enacted, then there would be no incentive for them ever become citizens or abide by American laws while residing within our borders.