In Chavez v. United States, the Supreme Court ruled on a dispute over land ownership in New Mexico. The case involved a Mexican citizen named Mariano S. Otero who had been granted land by the Mexican government prior to the Treaty of Guadalupe Hidalgo in 1848, which ended the Mexican-American War and ceded large portions of territory from Mexico to America including present-day New Mexico where Otero's property was located. After this treaty, an American citizen named Chavez claimed part of this same tract as public domain under U.S law because he believed that Otero's grant was invalid due to lack of proper documentation. The court held that even if there were flaws or irregularities with how original grants were made under Spanish or Mexican rule, they should still be recognized after territories became part of U.S jurisdiction unless Congress explicitly declared otherwise - something it hadn't done here. Therefore, Chavez could not claim any portion of Otero’s land as public domain since it had already been legally granted before becoming US territory.

In the dissenting opinion for Chavez v. United States, Justice Harlan argued that the majority's decision violated principles of justice and fairness by allowing a person to be tried twice for the same offense. He contended that this was in direct contradiction with the Fifth Amendment's protection against double jeopardy. Harlan also disagreed with the majority’s interpretation of “jeopardy,” arguing that it should not solely refer to risk but rather actual harm or loss suffered by an individual due to prosecution. Furthermore, he expressed concern about potential abuses of power if prosecutors were allowed to retry cases simply because they were dissatisfied with initial outcomes. Ultimately, Justice Harlan believed that once a jury had been empaneled and sworn in, any subsequent dismissal without reaching a verdict would constitute double jeopardy unless there was manifest necessity or consent from defendants.