In the 1902 case of Leach v. Burr, the United States Supreme Court dealt with a dispute over land ownership in California. The plaintiff, Leach, claimed that he had purchased a piece of property from an individual who had obtained it through preemption rights under federal law. However, this claim was contested by Burr and others who argued they held title to the same land based on Mexican land grants recognized by U.S treaty obligations following the Mexican-American War. The lower court ruled in favor of Burr and his associates. The Supreme Court upheld this decision upon appeal stating that when there is conflict between private claims based on preemption rights and those derived from foreign treaties (in this case Mexico), preference should be given to treaty-based claims as per Article VI of US Constitution which states "all Treaties made...under Authority of United States shall be supreme Law". This ruling reinforced respect for international agreements within American jurisprudence.

In the dissenting opinion for Leach v. Burr, it was argued that the majority's decision to uphold a lower court ruling in favor of a creditor who had purchased property at an unfairly low price during a forced sale was unjust and contrary to established legal principles. The dissenting justices believed that the debtor should have been allowed to redeem his property because he had not received fair value for it at the time of sale. They contended that allowing creditors to purchase debtors' properties at prices far below their actual worth would encourage predatory lending practices and result in unfair outcomes for debtors. Furthermore, they disagreed with the majority's interpretation of relevant state laws, arguing instead that these laws were intended to protect debtors from such exploitative situations.