Treason Under the Constitution

By Samuel Strom, J.D. | Legally reviewed by Laura Temme, Esq. | Last reviewed August 15, 2024

Article III of the U.S. Constitution defines treason as levying war against the United States or adhering and providing aid or comfort to its enemies. Although there have been relatively few treason cases in American history, the Supreme Court has clarified what it means to "levy war" and provide "aid or comfort" to enemies.
Treason is the only crime defined in the Constitution of the United States. It is the act of waging war against the United States or materially aiding its enemies.
The Framers of the U.S. Constitution intended to define treason narrowly after their experience with the English law of treason, which expanded the definition to cover many actions against the Crown.
The Framers also wanted to make it challenging to establish that someone committed treason. By defining treason in the Constitution, they restricted Congress's power to change the definition of the crime and the proof needed to establish charges of treason.
Since the Constitution's ratification, Congress has only brought treason charges 30 times. Few treason cases have ever reached the Supreme Court. Although there were several instances in early American history, the Court first sustained a treason conviction in 1947.

The Treason Clause
Article III, Section 3, Clause 1 of the U.S. Constitution states:
"Treason against the United States, shall consist only in levying War against them, or in adhering to their Enemies, giving them Aid and Comfort. No Person shall be convicted of Treason unless on the testimony of two Witnesses to the same overt Act, or on Confession in open Court."

Article III, Section 3, Clause 2 states:
"The Congress shall have Power to declare the Punishment of Treason, but no Attainder of Treason shall work Corruption of Blood, or Forfeiture except during the Life of the Person attainted."