Article Three treason. Some of these laws are still in effect. The well-known spies Julius and Ethel Rosenberg were charged with conspiracy to commit espionage, rather than treason. Historical cases In the United States, Benedict Arnold's name is considered synonymous with treason due to his collaboration with the British during the American Revolutionary War. This, however, occurred before the Constitution was written. Arnold became a general in the British Army, which protected him. 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 but were pardoned by President George Washington. Burr trial The most famous treason trial, that of Aaron Burr in 1807, resulted in acquittal. In 1807, on a charge of treason, Burr was brought to trial before the United States Circuit Court at Richmond, Virginia. The only physical evidence presented to the grand jury was General James Wilkinson's so-called letter from Burr, which proposed the idea of stealing land in the Louisiana Purchase. The trial was presided over by Chief Justice of the United States John Marshall, acting as a circuit judge. Since no witnesses testified, Burr was acquitted in spite of the full force of Jefferson's political influence thrown against him. Immediately afterward, Burr was tried on a misdemeanor charge and was again acquitted. Civil War During the American Civil War, treason trials were held in Indianapolis against Copperheads for conspiring with the Confederacy against the United States. In addition to treason trials, the federal government passed new laws that allowed prosecutors to try people for the charge of disloyalty. Various legislation was passed, including the Conspiracies Act of July 31, 1861. Because the law defining treason in the constitution was so strict, new legislation was necessary to prosecute defiance of the government. Many of the people indicted on charges of conspiracy were not taken to trial, but instead were arrested and detained. In addition to the Conspiracies Act of July 31, 1861, in 1862, the federal government went further to redefine treason in the context of the civil war. The act that was passed is entitled "An Act to Suppress Insurrection; to punish Treason and Rebellion, to seize and confiscate the Property of Rebels, and for other purposes". It is colloquially referred to as the "second Confiscation Act". The act essentially lessened the