United States v. Mann is a United States Supreme Court case that was decided in 1877. The case involved a dispute between the United States and a man named John Mann. Mann had been convicted of violating the Revenue Act of 1864, which prohibited the sale of distilled spirits without a license. Mann argued that the Act was unconstitutional because it violated the Fifth Amendment's prohibition against taking private property for public use without just compensation. The Supreme Court held that the Act was constitutional and that Mann's conviction was valid. The Court reasoned that the Act did not take Mann's property without just compensation because it did not require him to surrender his property. Instead, the Act merely imposed a tax on the sale of distilled spirits, which Mann was free to pay or not pay. The Court also noted that the Act did not prevent Mann from selling distilled spirits, but merely imposed a tax on the sale of such spirits. In conclusion, the Supreme Court held that the Revenue Act of 1864 was constitutional and that Mann's conviction was valid. The Court reasoned that the Act did not take Mann's property without just compensation and that it merely imposed a tax on the sale of distilled spirits.

In United States v. Mann, the Supreme Court was tasked with determining whether a federal statute that allowed for the forfeiture of property used to facilitate certain criminal offenses applied to an individual who had been convicted of violating a state law prohibiting gambling. The majority opinion held that the statute did not apply in this case because it only covered violations of federal laws and not those under state law. Justice Field dissented from this decision, arguing that Congress intended for the statute to cover any violation related to gambling regardless of its origin. He argued further that if Congress wanted such distinctions made between different types of violations then they would have included language explicitly making them in their legislation instead of leaving it open-ended as they had done here. Ultimately, he concluded by stating his belief that allowing states more control over matters like these could lead to confusion and inconsistency across jurisdictions which is why he felt strongly about upholding the original intent behind this particular piece of legislation even though it may have resulted in an unfavorable outcome for one party involved in this case specifically.