The U.S. Supreme Court case Western Fuel Company v. Garcia, Administrator of Souza in 1921 revolved around a dispute over the death benefits owed to the family of an employee who died while working for Western Fuel Company. The deceased was a resident and citizen of Portugal and his dependents lived there as well. Under California law at that time, if an injured worker had no dependents residing in the United States, then only burial expenses would be paid by the employer's insurance carrier with any remaining compensation going to the state treasury rather than overseas relatives or heirs. However, this conflicted with a treaty between Portugal and America which stated that citizens should receive equal treatment regardless of their location when it comes to civil rights protection including receiving damages for personal injury or death caused by acts done within jurisdictional boundaries. The court ruled against Western Fuel Co., stating that federal treaties supersede state laws under Article VI Clause 2 (the Supremacy Clause) of U.S Constitution; hence Portuguese beneficiaries were entitled to full compensation despite living abroad.

In the dissenting opinion for Western Fuel Company v. Garcia, Justice McReynolds disagreed with the majority's interpretation of maritime law and its application to this case. He argued that Souza was not a seaman under maritime law because he did not contribute to the function or mission of the vessel in any significant way, but rather performed duties related solely to his employment at Western Fuel Company. Therefore, according to Justice McReynolds, Souza should have been considered a longshoreman rather than a seaman and thus would be ineligible for protection under federal maritime laws. Furthermore, he contended that even if Souza were considered a seaman by some definitions of the term, his death occurred while on land performing tasks unrelated directly to navigation or commerce - activities which fall outside traditional interpretations of what constitutes "maritime service". Henceforth concluding that state workers' compensation laws should apply instead.