In Monroe v. United States (1901), the Supreme Court ruled on a case involving an individual who was convicted for using counterfeit money, despite his claims that he was unaware of its fraudulent nature. The defendant, Monroe, argued that the jury instructions were incorrect because they did not require proof of intent to defraud as part of the conviction. However, the Supreme Court disagreed and upheld his conviction. They stated that while intent is generally necessary in criminal cases to establish guilt beyond reasonable doubt, it's not required when dealing with counterfeit currency due to its potential harm on commerce and public confidence in monetary transactions. Therefore, even if someone innocently uses counterfeit money without knowing it's fake can be held criminally liable under federal law.

In the dissenting opinion for Monroe v. United States, Justice Harlan argued that the majority's decision to uphold a law allowing federal courts to try cases involving crimes committed on Native American reservations was unconstitutional. He contended that this violated the principle of tribal sovereignty and infringed upon rights reserved for states under the Constitution. Harlan believed that Congress did not have authority over these matters unless explicitly granted by treaty or statute, neither of which were present in this case. Furthermore, he disagreed with the majority's interpretation of previous court decisions regarding jurisdiction over Native American territories as being too broad and inconsistent with established legal principles concerning state and tribal rights.