When questions of this nature arise in a lawsuit between private
parties, the courts can, without notice to them, seek information
by communicating directly with the Department of State. It will
be given by a letter or certificate, and this will be received as
a conclusive mode of proof or as aiding the court in taking
judicial notice of historical facts.

So an official letter or certificate from the minister or consul
of a foreign power can be received and used as evidence as to
facts in controversy peculiarly within the knowledge of that
government.[Footnote: Gernon _v._ Cochran, Bee's Reports,
209.]

In prize cases, which must all be brought before the District
Court, an appeal is allowed directly to the Supreme Court of the
United States, although the judgments of the District Court
generally are reviewable only in an intermediate court. This
secures a prompt decision by the highest judicial authority of a
question which necessarily affects, in some degree, the foreign
relations of the United States.

But there may be cases affecting a vessel claimed as a prize
which are not brought to secure her forfeiture and so are not
prize cases. They may even to a greater extent affect our
relations to foreign governments. How far can the courts, in
dealing with these, govern their action by that of the executive?

This question came up for decision shortly after the adoption of
the Constitution. Great Britain and Spain were at war. A