Article III, Section 3 defines treason as ''levying War'' against the United States or adhering to enemies by giving them aid and comfort. Chief Justice John Marshall confined levying war''s meaning to actual armed conflict, ruling in Ex parte Bollman (1807) that ''if a body of men be actually assembled for the purpose of effecting by force a treasonable purpose, all those who perform any part are to be considered as traitors.'' However, there must be an actual assembling of armed people for the treasonable purpose to constitute levying war—mere planning or conspiracy doesn''t suffice. The Framers intentionally narrowed treason''s definition after experiencing English law, which expanded the crime to cover many actions against the Crown, making it a tool of political persecution. The Constitution requires testimony from two witnesses to the same overt act or confession in open court for conviction, creating the highest evidentiary standard for any federal crime and protecting citizens from politically motivated treason charges.