This is a little bit of history on treason laws and some acts of treason by people.
The abuses of the English law was specifically defined in the United States Constitution on treason. The only crime so defined. Article III Section 3 delineates treason as follows:
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.
The Congress has the power to declare the Punishment of Treason. No Attainder of Treason shall work Corruption of Blood, or Forfeiture except during the Life of the Person attainted.
Congress has, at times, passed statutes creating related offenses that undermine the government or the national security. (Like the sedition in the 1798, Alien and Sedition Acts, or espionage and sedition in the 1917 Espionage Act. Both do not require two witnesses.) For example, some well-known spies have been convicted of espionage rather than treason.
The Constitution does not itself create the offense. It restricts the definition. The first paragraph, permits Congress to create the offense and restricts any punishment for treason to only the convicted in the second paragraph. The crime is prohibited by legislation passed by Congress. The United States Code at 18 U.S.C. § 2381 states:
"whoever, owing allegiance to the United States, levies war against them or adheres to their enemies, giving them aid and comfort within the United States or elsewhere, is guilty of treason and shall suffer death, or shall be imprisoned not less than five years and fined under this title but not less than $10,000; and shall be incapable of holding any office under the United States."
This requires the testimony of two witnesses was inherited from the British Treason Act 1695.
Benedict Arnold was one of American history's most notorious traitors. His name is considered synonymous with the definition of traitor due to his collaboration with the British during the War of Independence. This occurred before the Constitution was written.
Since the Constitution came into effect, there have been fewer than 40 federal prosecutions for treason and even fewer convictions. Several men were convicted of treason in connection with the 1794 Whiskey Rebellion. President George Washington pardoned them.
The most famous treason trial was of Aaron Burr in 1807. It resulted in acquittal. It was politically motivated attempts to convict opponents of the Jeffersonian Embargo Acts and the Fugitive Slave Law of 1850 all failed.
After the American Civil War, no person involved with the Confederate States of America was tried for treason. There was however a number of leading Confederates, including Jefferson Davis and Robert E. Lee, were indicted. President Andrew Johnson gave those indicted amnesty as he left office in 1869.
In the Cold War there were frequent associations between treason and support for Communist-backed causes. The most memorable of these came from Senator Joseph McCarthy. He accused the Franklin Delano Roosevelt and Harry Truman administrations of "twenty years of treason." Senator Joseph McCarthy was chosen chair of the Senate Permanent Investigations Subcommittee. McCarthy investigated various government agencies for Soviet spy rings. He acted as a political fact-finder rather than a criminal prosecutor. The Cold War period saw few prosecutions for treason.
On October 11, 2006, a federal grand jury issued the first indictment for treason against the United States since 1952, charging Adam Yahiye Gadahn for videos in which he appeared as a spokesman for al-Qaeda and threatened attacks on American soil.
