In the case of Maggie J. Smith; Walker v. Dun, the Supreme Court of the United States was asked to decide whether a contract between two parties was valid and enforceable. The contract in question was between Maggie J. Smith and Walker, and it stated that Walker would pay Smith a certain amount of money in exchange for her relinquishing her right to a certain piece of property. The Supreme Court held that the contract was valid and enforceable. The Court reasoned that the contract was supported by consideration, meaning that both parties had given something of value in exchange for the other's promise. The Court also found that the contract was not against public policy, as it did not involve any illegal activity. The Court also held that the contract was not voidable due to the fact that Smith was a minor at the time the contract was made. The Court reasoned that Smith had the capacity to understand the nature of the contract and that she had voluntarily entered into it. Finally, the Court held that Walker was not liable for any damages that Smith may have suffered as a result of the contract. The Court reasoned that Smith had voluntarily entered into the contract and that she had not been misled or taken advantage of in any way.

Justice Field delivered the dissenting opinion in this case, arguing that the Court should not have reversed the decision of the Circuit Court. He argued that under Louisiana law, a married woman was allowed to own and control her separate property without interference from her husband. The Supreme Court had held otherwise, ruling that Walker had authority over Smith's property as he was her husband and head of household. Justice Field disagreed with this interpretation of Louisiana law, noting that it would be contrary to long-standing principles established by both state and federal courts which recognized a wife's right to manage her own property independently from any claim or interference by her husband. Furthermore, he noted that if such an interpretation were adopted then it could lead to serious consequences for women who owned their own businesses or other forms of real estate; they would no longer be able to exercise full control over these assets without fear of their husbands taking them away at will. Ultimately Justice Field concluded his dissent by stating his belief that allowing husbands absolute power over their wives' properties ran counter to public policy and justice itself.