Hepburn and Dundas v. Colin Auld was a case heard by the United States Supreme Court in 1803. The dispute arose when Hepburn and Dundas, two merchants from Baltimore, Maryland, sued Colin Auld for nonpayment of goods they had sold him on credit. The court found that the contract between the parties was valid under Maryland law but held that it could not be enforced because it violated a federal statute prohibiting such contracts as being against public policy. This ruling established an important precedent regarding state laws conflicting with federal statutes; namely, that if there is any conflict between them then the federal statute will take precedence over state law. Furthermore, this decision also set forth an early interpretation of what constitutes "public policy" in regards to contractual agreements and how courts should interpret such matters going forward.

In Hepburn and Dundas v. Colin Auld, the Supreme Court of the United States was asked to decide whether a state court had jurisdiction over a case involving citizens from different states. The majority opinion held that it did not have such jurisdiction, but Justice Samuel Chase dissented on this point. He argued that under Article III of the Constitution, Congress has granted state courts concurrent jurisdiction in cases between citizens of different states if those cases involve disputes over land titles or other matters arising out of contracts made within their respective jurisdictions. Furthermore, he noted that there is no express provision in either federal or state law which would limit such power to only certain types of controversies; thus any controversy between two parties who are citizens from different states should be heard by both federal and state courts alike. In conclusion, Justice Chase believed that since this particular case involved an issue related to contract rights - namely debt collection - then it fell squarely within the scope of concurrent jurisdiction as outlined by Article III and therefore should have been heard by both federal and state courts simultaneously.