United States v. Bostwick was a United States Supreme Court case that dealt with the issue of whether a person could be convicted of a crime based on circumstantial evidence. The case involved a man named Bostwick who was accused of stealing a horse from a government stable. The government argued that Bostwick had been seen in the vicinity of the stable shortly before the horse was stolen and that he had been seen riding away from the stable shortly after the theft. The government argued that this circumstantial evidence was sufficient to convict Bostwick of the crime. The Supreme Court ultimately ruled in favor of the government, holding that circumstantial evidence was sufficient to convict a person of a crime. The Court reasoned that circumstantial evidence was just as reliable as direct evidence and that it was up to the jury to decide whether the circumstantial evidence was sufficient to prove guilt beyond a reasonable doubt. The Court also noted that circumstantial evidence could be used to corroborate direct evidence and that it was not necessary for the government to prove guilt beyond a reasonable doubt solely on the basis of circumstantial evidence.

In United States v. Bostwick, the Supreme Court was asked to decide whether a defendant could be convicted of selling liquor without a license in violation of federal law when he had no knowledge that such activity was illegal. The majority opinion held that ignorance of the law is not an excuse and affirmed the conviction. Justice Field dissented from this decision, arguing that it would lead to unjust results and violate fundamental principles of justice by punishing people for actions they did not know were wrong or prohibited by law. He argued that if Congress intended to punish individuals who acted in good faith but unknowingly violated its laws, then it should have made those intentions clear through explicit language in the statute itself rather than leaving them open to interpretation by courts.