In the United States v. Chavez case in 1899, the Supreme Court ruled on a dispute over land grants in New Mexico that were made when it was still part of Mexico. The defendant, Mariano S. Otero, had purchased a large tract of land from José Antonio Chávez and later sold parts to various parties who then improved upon them. When the U.S government began investigating these transactions under its mandate to confirm or deny Mexican-era land grants after acquiring New Mexico through the Treaty of Guadalupe Hidalgo, they found irregularities with Chávez's original grant documents and declared them fraudulent. The court held that even if fraud existed in obtaining an original title from Mexican authorities (which wasn't definitively proven), subsequent innocent purchasers for value without notice should not be penalized by having their titles invalidated due to this earlier potential misconduct; they bought lands believing they were validly granted and invested money into improving them based on this belief. Therefore, while acknowledging some dubious circumstances surrounding Chávez's initial acquisition of his grant which warranted further investigation by lower courts before final confirmation could occur - such as whether he actually fulfilled conditions required for receiving it like settling families there - those who subsequently acquired portions from him did so legitimately under American law principles protecting bona fide purchasers against unrecorded claims or defects unknown at time of purchase.

In the dissenting opinion for United States v. Chavez, Justice Harlan argued that the majority's decision to uphold a conviction based on evidence obtained through an interpreter was fundamentally flawed. He contended that using an interpreter inherently introduced uncertainty and potential bias into the proceedings, as there was no way to guarantee that the translator had accurately conveyed both questions and responses without any personal interpretation or influence. Furthermore, he asserted that this practice violated defendants' constitutional rights by denying them their right to confront witnesses against them directly - in this case, being able to understand and respond immediately to accusations made in English. Therefore, according to Justice Harlan's dissenting view, such convictions should not be allowed under U.S law due its inherent unreliability and violation of fundamental legal principles.