Elijah Phelps, plaintiff in error, brought a case against Jacob Mayer. The dispute was over the ownership of a horse that had been sold to Phelps by Mayer. Phelps claimed he paid for the horse with cash and goods but Mayer argued that it was only on credit. After examining evidence from both parties, including testimony from witnesses who were present at the time of sale, the court found in favor of Elijah Phelps and ruled that he owned full title to the horse as payment had already been made according to their agreement.

In Elijah Phelps v. Jacob Mayer, the Supreme Court was asked to decide whether a contract between two parties could be enforced when it had been made without consideration and in violation of a state statute. The majority opinion held that the contract was unenforceable because it lacked consideration and violated public policy as expressed by the state law. In his dissenting opinion, Justice Grier argued that contracts should not be invalidated simply because they lack consideration or violate statutes; instead, he believed that courts should look at each case on its own merits and consider all relevant factors before deciding whether to enforce them or not. He further argued that if a court were to find an agreement valid despite lacking consideration or violating statutory provisions, then this would encourage people to enter into more agreements with confidence knowing their rights will be protected even if something goes wrong down the line.