The courts of the United States, in controversies involving matters affecting the foreign relations of the general government, acknowledge in a certain degree a dependence upon the executive department. If they have a treaty to construe, any construction of it as to the point in question already given by the State Department will be followed, unless plainly wrong. If it becomes material to determine whether a certain country is subject to a certain power, and the President of the United States has dealt with that question (as by recognizing or refusing to recognize a minister accredited to the United States), his action will be accepted as conclusive. His proceedings would have like weight if taken within the limits of his authority with respect to the government of one of the United States.[Footnote: Luther _v._ Borden, 7 Howard's Reports, 1.] 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?