Here's a couple of links that should provide the details you need.  I've included the paragraphs that state that Tokyo Rose was the only person ever pardoned after a treason conviction.\n\n\nhttp://www.discoverthenetwork.org/Articles/Innocent%20of%20Treason.htm\n\n"In 1977 Iva Toguri d'Aquino was pardoned fully and unconditionally by President Gerald Ford, who, in his last official act, restored her citizenship. She was the only American ever pardoned after being convicted of treason. "\n\n\nhttp://forejustice.org/wc/tr/tokyo_rose_040503.htm\n\n"In November 1976 Wayne Merrill Collins, the son of Iva’s trial lawyer filed a presidential pardon petition for Iva. The public disclosures supporting her innocence were so convincing by that time, that on January 19, 1977, in one of his last acts prior to leaving office, President Ford pardoned Iva Toguri d’Aquino. She is the only person convicted of treason in this country that has been pardoned."