In French, Trustee v. Hay, the United States Supreme Court was asked to decide whether a deed of trust was valid. The deed of trust was created by a man named Hay, who had borrowed money from a bank and used his land as collateral. The deed of trust stated that if Hay failed to repay the loan, the bank would have the right to sell the land. The Supreme Court held that the deed of trust was valid. The Court reasoned that the deed of trust was a valid contract between Hay and the bank, and that the bank had the right to enforce the terms of the contract. The Court also held that the deed of trust was not invalidated by the fact that it was not recorded in the public records. The Court's decision in French, Trustee v. Hay established that a deed of trust is a valid contract and that it can be enforced even if it is not recorded in the public records. This decision has been cited in numerous cases since then, and it has been used to support the validity of deeds of trust in many states.

In French v. Hay, the Supreme Court was asked to decide whether a deed of trust created by an individual in favor of another person could be enforced against the assignee of that individual's estate. The majority opinion held that it could not, as such a transfer would violate public policy and render the assignment voidable at law. However, Justice Field dissented from this decision on two grounds: firstly, he argued that there was no legal basis for denying enforcement of such transfers; secondly, he noted that if any party had been harmed by this transaction they should have raised their objections before or during its execution rather than after it had already taken place. Ultimately, Justice Field concluded that since all parties involved were aware of the terms and conditions surrounding this particular deed when it was executed - including those related to its enforceability - then these same terms should remain binding upon them regardless of subsequent changes in ownership or title status.