constructive treasons by the common law courts. The
constitutional definition is, of course, much more restrictive than the
enumeration of treasons in the English statute, but like that statute,
it is emphatically a limitation on the power of government to define
treason and to prove its existence. The rigid and exclusive definition
of treason takes from Congress all power to define treason and
prescribes limitations on the power to prescribe punishment thereupon.

LEVYING WAR

Early judicial interpretation of the meaning of treason in terms of
levying war was conditioned by the partisan struggles of the early
nineteenth century, in which were involved the treason trials of Aaron
Burr and his associates. In Ex parte Bollman,[725] which involved two of
Burr's confederates, Chief Justice Marshall, speaking for himself and
three other Justices, confined the meaning of levying of war to the
actual waging of war. "However flagitious may be the crime of conspiring
to subvert by force the government of our country, such conspiracy is
not treason. To conspire to levy war and actually to levy war, are
distinct offences. 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. So far has this principle been
carried, that * * * it has been determined that the actual enlistment of
men, to serve against the government, does not amount to the levying of
war."[726] Chief Justice Marshall was careful, however, to state that
the Court did not mean that no person could be guilty of this crime who
had not appeared in arms against the country. "On the contrary, if it be
actually levied, that is, if a body of men be actually assembled, for
the purpose of effecting by force a treasonable purpose, all those who
perform any part, however minute, or however remote from the scene of
action, and who are actually leagued in the general conspiracy, are to
be considered as traitors. But there must be an actual assembling of
men, for the treasonable purpose, to constitute a levying of war."[727]
On the basis of these considerations and due to the fact that no part of
the crime charged had been committed in the District of Columbia, the
Court held that Bollman and Swartwout could not be tried in the District
and ordered their discharge. He continued by saying that "the crime of
treason should not be extended by construction to doubtful cases" and