United States v. Auffmordt was a United States Supreme Court case that dealt with the issue of whether a defendant could be convicted of a crime if the indictment failed to allege the essential elements of the offense. The defendant, Auffmordt, was charged with the crime of selling liquor without a license. The indictment failed to allege that the defendant had knowledge of the illegality of the sale. The Supreme Court held that the indictment was insufficient to support a conviction because it failed to allege the essential element of knowledge. The Court reasoned that knowledge of the illegality of the sale was an essential element of the offense and that the indictment must allege this element in order to support a conviction. The Court further held that the defendant could not be convicted on the basis of the indictment because it failed to allege the essential element of knowledge. The Court's decision in United States v. Auffmordt established the principle that an indictment must allege all of the essential elements of the offense in order to support a conviction. This decision has been cited in numerous subsequent cases and has become an important part of criminal law.

In United States v. Auffmordt, the Supreme Court was asked to decide whether a patentee of an invention could sue for damages in a court of equity when their patent had been infringed upon by another party. The majority opinion held that such suits were not allowed under existing law and thus dismissed the case. However, Justice Field dissented from this decision and argued that it should be possible for patentees to bring suit against those who have infringed on their patents in order to receive compensation for any losses they may have suffered as a result of the infringement. He further argued that allowing such suits would help protect inventors’ rights and encourage innovation by providing them with some assurance that they will be able to benefit financially from their inventions if someone else uses them without permission or authorization.