Albert J. Beveridge,
The Life of John Marshall, Volume 3…
“ Marshall then read, with solemn impressiveness, these words from the Constitution of the United States: "Treason against the United States shall consist only in levying war against them, or in adhering to their enemies, giving them aid and comfort."To support the charge against Bollmann and Swartwout, said Marshall, "war must be actually levied.... To conspire to levy war, and actually to levy war, are distinct offenses. The first must be brought into open action by the assemblage of men for a purpose treasonable in itself, or the fact of levying war cannot have been committed." ”
