United States v. Henry was a United States Supreme Court case that addressed 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 Court held that the evidence was inadmissible and that the defendant could not be convicted. The case involved a defendant, Henry, who was charged with the possession of stolen goods. The evidence used to convict him was obtained through a search and seizure that was conducted without a warrant. The Court held that the search and seizure was illegal and that the evidence obtained was inadmissible. The Court reasoned that the Fourth Amendment of the United States Constitution protects citizens from unreasonable searches and seizures and that the evidence obtained in this case was obtained in violation of that amendment. The Court also held that the exclusionary rule applied in this case. The exclusionary rule states that evidence obtained in violation of the Fourth Amendment is inadmissible in court. The Court reasoned that the exclusionary rule was necessary to protect citizens from unreasonable searches and seizures and to ensure that the government does not use illegally obtained evidence to convict individuals. The Court ultimately held that the evidence obtained in this case was inadmissible and that the defendant could not be convicted. This case established the principle that evidence obtained in violation of the Fourth Amendment is inadmissible in court and that the exclusionary rule applies in such cases.

Justice Field delivered the dissenting opinion in United States v. Henry, arguing that the court should not have reversed its earlier decision in Ex Parte Watkins. He argued that Congress had no authority to pass a law which would allow for an appeal from a circuit court's ruling on habeas corpus proceedings, as this was outside of their constitutional powers and could potentially lead to further encroachments upon judicial power by Congress. Furthermore, he noted that while it may be true that there were some errors made by the lower courts in this case, they did not rise to such a level as to warrant overturning precedent established by prior decisions of the Supreme Court. In conclusion, Justice Field believed that reversing Ex Parte Watkins was unwarranted and unnecessary given all of these factors and thus dissented from the majority opinion.