Article III, Section 3 defines treason as the only crime specified in the Constitution, consisting of either levying war against the United States or adhering to its enemies by giving them aid and comfort. The Framers narrowly defined treason after experiencing England''s expansive treason laws that punished many actions against the Crown. Conviction requires testimony from two witnesses to the same overt act or confession in open court, a higher standard than any other crime. The Supreme Court ruled in Cramer v. United States (1945) that prosecutors must prove both concrete action and intent to betray the nation, not merely traitorous thoughts. Levying war means assembling a body of people to accomplish a treasonable purpose by force, with all participants in the conspiracy considered traitors regardless of their proximity to the action. The overt act requirement ensures treasonous plans have moved from thought to action. This strict definition and proof standard make treason prosecutions rare in American history.