Airhart v. Massieu is a United States Supreme Court case that was decided in 1878. The case involved a dispute between two parties over a contract for the sale of a steamboat. The plaintiff, Airhart, had contracted with the defendant, Massieu, to purchase a steamboat for $2,000. Airhart had paid $1,000 of the purchase price and was to pay the remaining $1,000 upon delivery of the steamboat. However, Massieu failed to deliver the steamboat and Airhart sued for breach of contract. The Supreme Court held that Airhart was entitled to recover the $1,000 he had paid, plus interest, as damages for the breach of contract. The Court reasoned that Airhart had already paid the $1,000 and was entitled to recover it, even though the steamboat had not been delivered. The Court also held that Airhart was entitled to recover interest on the $1,000, as he had been deprived of the use of the money due to Massieu's breach of contract. In conclusion, the Supreme Court held that Airhart was entitled to recover the $1,000 he had paid, plus interest, as damages for the breach of contract. The Court reasoned that Airhart had already paid the $1,000 and was entitled to recover it, even though the steamboat had not been delivered. The Court also held that Airhart was entitled to recover interest on the $1,000, as he had been deprived of the use of the money due to Massieu's breach of contract.

Justice Field delivered the dissenting opinion in Airhart v. Massieu, arguing that the court should have granted a writ of error to review the case. He argued that although there was no dispute over whether or not Airhart had been convicted and sentenced by a jury in California, it was unclear if he had received due process under state law. The majority held that since Airhart did not raise this issue before his conviction became final, he could not challenge it on appeal; however Justice Field disagreed with this reasoning as he believed an individual's right to due process is fundamental and should be protected regardless of when they choose to bring up their claim. Furthermore, Justice Field noted that while California may have provided for some form of judicial review after conviction has become final (in certain cases), such proceedings are discretionary rather than mandatory which means individuals cannot rely on them for protection against violations of their rights during trial proceedings. Thus, according to Justice Field's dissent, denying writs of error in cases like these would leave individuals without any recourse if they were denied due process at trial - something which goes against basic principles underlying our justice system