Blake 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 was obtained through an illegal search and seizure. The case involved a man named William Blake 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 ruled in favor of Blake, finding that the evidence obtained through the illegal search and seizure was inadmissible in court. The Court held that the Fourth Amendment of the United States Constitution protects citizens from unreasonable searches and seizures and that any evidence obtained through such searches and seizures is inadmissible in court. The Court also held that the exclusionary rule applies to all federal courts, meaning that any evidence obtained through an illegal search and seizure is inadmissible in court. The ruling in Blake v. United States established the precedent that evidence obtained through an illegal search and seizure is inadmissible in court and that the exclusionary rule applies to all federal courts. This ruling has been used in numerous cases since then to protect citizens from unreasonable searches and seizures.

Justice Field delivered the dissenting opinion in Blake v. United States, arguing that the court should not have reversed its earlier decision in Ex Parte Siebold (1880). He argued that Congress had no authority to pass a law requiring federal officers to enforce state election laws and punish violations of them as if they were federal crimes. Furthermore, he argued that such a law was unconstitutional because it violated both the Tenth Amendment's reservation of powers to states and Article I Section 8's enumeration of congressional power. Justice Field also noted that even if Congress did have this power, it would be an abuse for them to exercise it without providing any guidance or standards on how these laws should be enforced. Finally, he concluded by noting that allowing Congress to pass such a law would lead down a slippery slope towards further encroachments upon state sovereignty which could ultimately destroy our constitutional system of government.