William and James Brown and Company brought a case against Thomas M'Gran to the Supreme Court in 1840. The company argued that they had loaned money to M'Gran, who was then obligated to pay it back with interest. However, when the time came for repayment, M’Gran refused. As such, William and James Brown and Company sued him for breach of contract. After hearing both sides of the argument, the Supreme Court ruled in favor of William and James Brown & Co., ordering that M’Gran must repay them their original loan plus interest as per his contractual agreement with them. This ruling set an important precedent regarding contracts between parties which has been used by courts ever since as guidance on how similar cases should be handled going forward.

The dissenting opinion in the case of William and James Brown and Company v. Thomas M'Gran argued that the defendant should not be held liable for a debt incurred by his father, who had died before it was due. The majority opinion found that since the son had accepted benefits from his father's estate, he could be held responsible for any debts owed to creditors at the time of death. However, Justice Story dissented on this point because there was no evidence presented showing that Thomas M'Gran knew about or consented to taking on these liabilities when accepting assets from his father's estate. Furthermore, Story argued that even if such knowledge existed, it would still be unfair to hold him accountable as he did not personally enter into any contract with William and James Brown and Company nor benefit financially from their services rendered prior to his father’s death.