In Koontz v. Northern Bank, the Supreme Court of the United States was asked to decide whether a bank could be held liable for failing to pay a note that had been endorsed by a third party. The plaintiff, Koontz, had endorsed a note for a third party, and the defendant, Northern Bank, had accepted the note and promised to pay it. However, the bank failed to pay the note, and Koontz sued for breach of contract. The Supreme Court held that the bank was liable for failing to pay the note, even though the note had been endorsed by a third party. The Court reasoned that the bank had accepted the note and had promised to pay it, and thus had a duty to fulfill its promise. The Court also held that the bank was not entitled to any defenses that the third party might have had, since the bank had accepted the note without any knowledge of the third party's defenses. In conclusion, the Supreme Court held that the bank was liable for failing to pay the note, and that the bank was not entitled to any defenses that the third party might have had. This decision established that banks are liable for failing to pay notes that have been endorsed by third parties.

In the case of Koontz v. Northern Bank, the Supreme Court was asked to decide whether a bank could be held liable for failing to pay out money that had been deposited with it by an individual who had since died. The majority opinion found in favor of the bank and held that no liability existed because there was no contract between them and the depositor's estate. However, Justice Field dissented from this decision on two grounds: firstly, he argued that banks should not be allowed to escape their obligations simply because they are dealing with deceased persons; secondly, he contended that if a person deposits money into a bank then they have created an implied contract which obligates both parties regardless of any change in circumstances such as death or bankruptcy. In conclusion, Justice Field believed that banks should not be able to avoid responsibility when someone dies after having entrusted them with their funds.