Harvey v. United States was a United States Supreme Court case that dealt with the issue of whether a defendant could be convicted of a crime if the evidence presented at trial was obtained through an illegal search and seizure. The case involved a man named Harvey who was charged with receiving stolen goods. The evidence used to convict him was obtained through a search of his home without a warrant. The Supreme Court held that the evidence obtained through the illegal search and seizure was inadmissible and that Harvey could not be convicted on the basis of it. The Court reasoned that the Fourth Amendment of the United States Constitution protects citizens from unreasonable searches and seizures and that the evidence obtained through the illegal search and seizure was in violation of this amendment. The Court also held that the exclusionary rule applied in this case, meaning that any evidence obtained through an illegal search and seizure was inadmissible in court. The decision in Harvey v. United States established the precedent that evidence obtained through an illegal search and seizure is inadmissible in court and cannot be used to convict a defendant. This decision has been cited in numerous cases since then and has become an important part of Fourth Amendment jurisprudence.

Justice Field delivered the dissenting opinion in Harvey v. United States, arguing that the majority's decision was incorrect and should be overturned. He argued that a contract between two parties is binding unless it has been modified or rescinded by mutual consent of both parties. In this case, he noted that there had been no such agreement to modify or rescind the original contract between Harvey and his partner; thus, any subsequent agreements made with third-parties were invalid as they did not supersede the original terms of their partnership agreement. Furthermore, Justice Field asserted that even if one party could unilaterally change an existing contract without consulting their partner first, then it would create too much uncertainty for businesses who rely on contracts to protect themselves from potential losses due to unforeseen circumstances. Therefore, he concluded that since there was no evidence of mutual assent between Harvey and his partner regarding changes to their initial agreement - nor any indication of fraud or misrepresentation - then all subsequent agreements involving third-parties should be considered void ab initio (from its inception).