This Supreme Court case was between Wyllys Lyman, George P. Marsh, John Peck and John H. Peck (plaintiffs in error) and the President, Directors and Company of the Bank of the United States (defendants). The plaintiffs had brought a suit against the defendants for an alleged breach of contract concerning a loan made by them to one William Buell. The court found that there was no evidence presented to support any claim that Buell had ever been authorized or empowered by his creditors to borrow money from the bank on their behalf; therefore they could not be held liable for repayment as it would constitute an illegal act under state law at that time. Furthermore, even if such authorization did exist, it would have been void due to its violation of public policy which prohibited individuals from borrowing money without proper security or collateral being provided first. Therefore, this ruling determined that neither party could recover damages from each other as both parties were equally culpable in violating state laws governing contracts involving loans made with insufficient security or collateral given beforehand.

In the dissenting opinion of this case, Justice McLean argued that the Bank of the United States was a private corporation and not an arm of Congress. He stated that it had been created by individuals who were authorized to use their own funds for its establishment, and as such should be treated like any other private company. Furthermore, he maintained that since no public money had been used in creating or maintaining the bank, it could not be considered part of Congress' powers under Article I Section 8 Clause 18 (the Necessary and Proper Clause). Therefore, he concluded that state laws regulating banking activities applied to the Bank just as they would any other business entity.