O.B. and O.S. Latham v. United States was a case heard by the United States Supreme Court in 1869. The case involved two brothers, O.B. and O.S. Latham, who were charged with violating the Revenue Act of 1862. The Act imposed a tax on the sale of distilled spirits and required that all persons engaged in the business of distilling spirits must obtain a license from the government. The Lathams had been operating a distillery without a license and were charged with violating the Act. The Lathams 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 disagreed and held that the Act was constitutional. The Court reasoned that the Act was a valid exercise of Congress' power to tax and regulate commerce, and that the tax imposed was not a taking of private property. The Court also held that the Act did not violate the Fifth Amendment because the tax was imposed on the sale of distilled spirits, not on the distillery itself. The Court's decision in O.B. and O.S. Latham v. United States established that Congress has the power to impose taxes on the sale of goods and services, and that such taxes do not constitute a taking of private property. The decision also reaffirmed the principle that the Fifth Amendment does not prohibit the government from imposing taxes on the sale of goods and services.

In the case of O.B. and O.S Latham v United States, the Supreme Court was asked to decide whether a contract between two parties could be enforced by one party against another when it had been made in violation of an existing law or regulation from Congress. The majority opinion held that such contracts were not enforceable, but Justice Field dissented on this point, arguing that if both parties entered into a contract with full knowledge of its illegality then they should be bound by it regardless of any laws or regulations which may have been violated in making it. He argued further that allowing such contracts to stand would encourage people to enter into agreements without fear of legal repercussions for violating existing laws and regulations; thus providing greater freedom for individuals while also protecting them from being taken advantage of due to their ignorance about applicable laws and regulations at the time they make their agreement