THE CONSTITUTION

Article III

Section 3. 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 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.

Treason was high on the minds of the Framers of the Constitution. They had just completed a war for independence acts of treason were common. In their minds it was the most egregious of crimes...but they didn't want the courts going overboard on it. Attainder means dishonor and the taking away of civil rights ... this dishonor is not extended to relatives.
:)