The Manila Prize Cases, decided by the U.S. Supreme Court in 1902, revolved around the legality of American naval actions during the Spanish-American War. The case specifically dealt with goods seized from vessels near Manila Bay in Philippines shortly after Spain had ceded control of the territory to America but before a formal peace treaty was ratified by Congress. The owners of these goods argued that since hostilities had ceased and Spain no longer controlled Philippines at the time their property was taken, it should be returned to them as per international law governing wartime seizures. However, in its decision, the court ruled against this argument stating that war does not end when one side surrenders or loses control over territories; instead it ends only when a formal peace agreement is signed and ratified by both parties involved. Therefore, according to this interpretation of international law on warfare and prize (seizure), American forces were within their rights to seize enemy property until such an agreement came into effect - even if actual fighting had stopped or territorial control changed hands prior to it.

In the dissenting opinion for The Manila Prize Cases, Justice Harlan argued that the U.S. Constitution does not grant Congress or the President authority to acquire territory for purposes other than making it a state. He contended that by taking control of territories like Puerto Rico and Guam without intending them to become states, they were essentially creating colonies which was against American principles. Furthermore, he disagreed with imposing duties on goods from these territories as if they were foreign countries rather than part of America itself. Harlan asserted this action violated constitutional provisions regarding uniformity in taxation across all states and territories under U.S jurisdiction. In essence, his argument centered around upholding democratic ideals enshrined in the constitution - no taxation without representation and equal rights for all citizens regardless of their geographical location within U.S jurisdiction.