Smith and Buchanan v. The Delaware Insurance Company was a case heard by the United States Supreme Court in 1813. At issue was whether Smith and Buchanan, two merchants from Philadelphia, were entitled to recover damages for goods that had been lost at sea while insured with The Delaware Insurance Company. Smith and Buchanan argued that they should be compensated because the insurance company had failed to provide them with proper notice of their policy's expiration date before it lapsed. However, The Delaware Insurance Company argued that since there was no written agreement between them regarding notification of policy expiration dates, Smith and Buchanan could not hold them liable for any losses incurred after the policy expired without warning or prior knowledge on their part. Ultimately, the Supreme Court sided with Smith and Buchanan ruling that an implied contract existed between both parties which obligated The Delaware Insurance Company to notify its customers when policies were about to expire so as not to leave them unprotected against potential losses due to unforeseen circumstances such as those experienced by Smith & Buchannan in this case.

In Smith and Buchanan v. The Delaware Insurance Company, the Supreme Court was asked to decide whether a policy of insurance issued by an out-of-state insurer could be enforced in a state court. Justice Johnson wrote the dissenting opinion, arguing that states should not have jurisdiction over contracts made outside their borders because it would interfere with Congress's exclusive power to regulate commerce between states. He argued that allowing such suits would lead to confusion and uncertainty for insurers who may find themselves subject to multiple jurisdictions when they issue policies across state lines. Furthermore, he noted that if each state had its own laws governing interstate contracts then there would be no uniformity or consistency among them which could create further complications for those involved in interstate transactions. Finally, he concluded that since Congress has already passed legislation regulating commerce between states it is unnecessary for individual states to do so as well and thus any attempt by them should be struck down as unconstitutional interference with federal authority.