Graham v. United States was a Supreme Court case that addressed the issue of whether a person could be convicted of a crime if the act was not specifically prohibited by a law. The case involved a man named William Graham, who was convicted of selling liquor without a license. The Supreme Court ruled that the conviction was valid, even though there was no specific law prohibiting the sale of liquor without a license. The Court reasoned that the sale of liquor without a license was a violation of the public policy of the United States, and that the government had the right to punish such an act. The Court also noted that the government had the right to punish any act that was contrary to the public policy of the United States, even if there was no specific law prohibiting it. The Court's ruling in Graham v. United States established the principle that a person can be convicted of a crime even if the act was not specifically prohibited by a law. This principle has been applied in many subsequent cases, and is still used today.

In Graham v. United States, the Supreme Court was asked to decide whether a person could be convicted of treason for providing aid and comfort to Confederate forces during the Civil War. The majority opinion held that such an act constituted treason under Article III of the Constitution, but Justice Field dissented from this decision. He argued that it would be unjust to punish someone who had acted out of loyalty or sympathy towards their home state rather than with any intent to overthrow the government or give aid and comfort to its enemies. Furthermore, he noted that there were no laws in place at the time which prohibited citizens from aiding either side in a civil war; thus punishing them retroactively for doing so would violate due process rights guaranteed by both federal law and common sense principles of justice.