In Robert Fenwick v. Eliza Chapman and Robert Chapman, the Supreme Court of the United States heard a case concerning an alleged breach of contract between two parties. The plaintiff in error, Robert Fenwick, had entered into a contract with Eliza and Robert Chapman to purchase their slaves for $2,000; however, he later refused to pay them after learning that one of the slaves was pregnant at the time of sale. The defendants argued that they were entitled to payment regardless because pregnancy is not grounds for rescission under Virginia law. Ultimately, Chief Justice Taney ruled in favor of the Chapmans on appeal from a lower court decision against them; he held that since there was no evidence presented by either party as to whether or not it was known at the time of sale that one slave would be pregnant soon thereafter (and thus could have been excluded from consideration), then both parties must bear any losses resulting from this unforeseen event equally.

In the case of Robert Fenwick v. Eliza Chapman and Robert Chapman, by Kitty Chapman their mother and next friend, the dissenting opinion was that a court should not be able to interfere with an agreement between two parties unless there is evidence of fraud or coercion. The majority opinion held that courts could intervene in such agreements if they were deemed to be against public policy or immoral. However, Justice McLean argued that this would give too much power to the judiciary as it would allow them to decide what constituted morality on a case-by-case basis without any clear guidelines for doing so. He further argued that allowing courts to do this could lead them down a slippery slope where they become overly involved in matters which are best left up to individuals themselves rather than being decided by judges who may have different moral views from those of society at large. In conclusion, Justice McLean believed that while some contracts might need judicial intervention due to fraud or coercion, most should remain outside of court interference as long as both parties agree upon its terms willingly and without duress.