It is little remembered now, but in 1865 there was a brief attempt to conduct treason trials against Confederate generals. On June 7, 1865, U.S. District Judge John C. Underwood in Norfolk, Virginia issued indictments against Lee, Longstreet, Early and other Confederate generals on charges of treason. Lee wrote to General Grant asking if the terms granted at Appomattox were still in effect. Furious at this attempt to undo his work, Grant immediately wrote to Secretary of War Stanton:
In my opinion the officers and men paroled at Appomattox Court-House, and since, upon the same terms given to Lee, cannot be tried for treason so long as they observe the terms of their parole. This is my understanding. Good faith, as well as true policy, dictates that we should observe the conditions of that convention. Bad faith on the part of the Government, or a construction of that convention subjecting the officers to trial for treason, would produce a feeling of insecurity in the minds of all the paroled officers and men. If so disposed they might even regard such an infraction of terms by the Government as an entire release from all obligations on their part. I will state further that the terms granted by me met with the hearty approval of the President at the time, and of the country generally. The action of Judge Underwood, in Norfolk, has already had an injurious effect, and I would ask that he be ordered to quash all indictments found against paroled prisoners of war, and to desist from further prosecution of them.
Grant then saw President Johnson. Initially Johnson said that the treason trials should proceed. Grant said he would immediately resign his commission if the Government went back on what he pledged at Appomattox. Johnson backed down and had the indictments quashed. Grant then wrote back to Lee on June 20, 1865 saying that the terms of Appomattox would be observed. He did not mention that it took his threat of resignation to accomplish it.