The U.S. Supreme Court case Jover Y Costas v. Insular Government of the Philippine Islands in 1910 revolved around a dispute over property rights and taxation in the Philippines, which was then under American control following the Spanish-American War. The plaintiff, Jover Y Costas, contested that his properties were being unjustly taxed by the insular government because they had been incorrectly classified as urban rather than rural lands - a classification that resulted in higher taxes. He argued this violated his rights to equal protection under law as guaranteed by the U.S Constitution's Fourteenth Amendment. However, the court ruled against him stating that constitutional protections did not automatically extend to territories controlled by America but not incorporated into it (like Puerto Rico or Guam). Therefore, these territories could enact their own tax laws even if they differed from those on mainland USA without violating any constitutional principles.

The dissenting opinion in the case of Jover Y Costas v. Insular Government of the Philippine Islands argued that the majority's decision was inconsistent with previous rulings and principles established by the Supreme Court. The dissent took issue with how property rights were handled, arguing that under Spanish law, which was applicable at the time when Jover acquired his land, he had a valid title to it. They contended that this should have been recognized even after American sovereignty over Philippines began because international law respects existing private property rights upon change of sovereignty unless explicitly stated otherwise by treaty or legislation. Therefore, they believed Jover’s ownership should not be invalidated just because he failed to register his land within a certain period as required by later U.S laws applied retroactively in Philippines.