In the 1902 Supreme Court case Sena v. United States, the court ruled on a matter concerning land grants in New Mexico. The plaintiff, Sena, claimed ownership of certain lands under an old Spanish grant which had been confirmed by Congress but not yet patented. The defendant was the U.S government who had sold parts of this land to other parties. The Supreme Court held that until a patent is issued for such lands (which officially transfers title from federal ownership), they remain public lands subject to disposal by the government under various preemption and homestead laws. Therefore, even though Sena's claim was based on a Congressional confirmation of his Spanish grant, he did not have legal title or exclusive possession rights over these lands until he received an official patent from the U.S Government.

In the dissenting opinion for Sena v. United States, Justice Harlan argued that the majority's decision to uphold a conviction based on evidence obtained through an illegal search was fundamentally flawed. He contended that this ruling undermined Fourth Amendment protections against unreasonable searches and seizures, which he believed were essential safeguards of individual liberty. In his view, allowing illegally obtained evidence to be used in court would incentivize law enforcement officials to disregard constitutional rights in their pursuit of convictions. Furthermore, he asserted that such a policy could lead to abuses of power and erode public trust in the justice system. Therefore, Justice Harlan concluded that any evidence gained from an unlawful search should be excluded from trial proceedings as a matter of principle.