In the case of William B. Dean v. Nathan Mason et al., Dean appealed a decision by the Supreme Court of Georgia that denied him his right to recover damages for an injury he sustained while working on a vessel owned by Mason and others. The court found in favor of Mason, ruling that since Dean was employed as a seaman, he could not bring suit against his employers under state law because seamen were not considered citizens at the time and therefore did not have legal standing to sue their employers for injuries they suffered during employment. However, the U.S Supreme Court reversed this decision, finding that seamen are indeed citizens with full rights under federal laws and thus can seek redress from their employers if injured while performing duties related to their employment aboard vessels owned or operated by those same employers. This ruling established important precedent regarding maritime labor law which has been upheld ever since its initial establishment in 1857

In the dissenting opinion of William B. Dean v. Nathan Mason et al., Justice Grier argued that a state court had no jurisdiction to decide a case involving title to land located in another state, as it was an issue for the federal courts alone. He further stated that even if there were some evidence of fraud or mistake on behalf of one party, this did not give the state court any authority over such matters since they are exclusively within the purview of federal law and should be decided by Congress or other competent authorities under their control. Finally, he noted that while states may have concurrent jurisdiction with respect to certain issues related to real estate titles, these must still be determined according to principles established by Congress and cannot be overruled by individual states without violating constitutional provisions protecting interstate commerce and uniformity among all states in regards to property rights.