The Monte Alegre and the Rainha de Los Anjos was a case heard by the US Supreme Court in 1822. The Portuguese Consul General, Libellant, brought suit against two ships for damages incurred when they were detained while attempting to leave port without paying customs duties. The court found that the vessels had been wrongfully seized and ordered their release with compensation for any losses suffered as a result of their detention. Furthermore, it held that foreign consuls have exclusive jurisdiction over matters concerning foreign vessels within American ports and waters; thus, no other authority could interfere with such matters without permission from said consuls. This ruling established an important precedent regarding international law which is still applicable today: namely, that foreign governments may exercise certain rights on behalf of its citizens or property even if those rights are not recognized under domestic laws.

In The Monte Alegre and the Rainha de Los Anjos, the Portuguese Consul General libellant argued that a vessel owned by him had been wrongfully seized by an American privateer. The Supreme Court held that while it was true that Portugal was neutral in the war between Spain and America at the time of seizure, this did not necessarily mean that all vessels belonging to Portuguese citizens were exempt from capture. Furthermore, they found no evidence to suggest any wrongdoing on behalf of either party involved in this case. Therefore, they concluded there was insufficient proof for restitution or damages to be awarded to the libellant. Ultimately, their decision favored neither side as both parties failed to provide sufficient evidence for their claims.