In the case of Castillo v. McConnico, 1897, the U.S Supreme Court dealt with a dispute over land ownership in New Mexico. The plaintiff, Castillo, claimed that he had inherited the land from his ancestors who had received it as a grant from Spain before Mexico gained independence and subsequently ceded to United States control under the Treaty of Guadalupe Hidalgo. However, defendant McConnico argued that no such grant existed or was recognized by American law after conducting an investigation through a commission established by Congress to review Spanish and Mexican land grants in territories acquired by America. The court ruled in favor of McConnico stating that there was insufficient evidence proving existence or recognition of any such Spanish Land Grant for Castillo's ancestors prior to American acquisition of these territories.

In the dissenting opinion of Castillo v. McConnico, 1897, Justice Harlan argued that the majority's decision was a misinterpretation of the Fourteenth Amendment. He contended that this amendment was designed to protect all citizens from state laws infringing upon their rights and privileges as U.S. citizens; it did not grant states absolute power over civil rights within their borders without federal oversight or intervention. Harlan believed that Louisiana’s law allowing for seizure and sale of property without due process violated these protected rights under the Constitution. The majority's ruling effectively allowed states to bypass constitutional protections by simply declaring such actions legal under state law, which he saw as a dangerous precedent undermining fundamental principles of justice and fairness in American society.