The Zimmermann telegram of 1917, the attempt of the German government to bring Mexico into World War I on the side of the Central Powers, is a well-known diplomatic episode because it is generally conceded to be one of the series of factors which convinced President Woodrow Wilson of the efficacy of abandoning his policy of neutrality. In return for her co-operation, and upon the successful conclusion of the war, Mexico was to “recover the lost territory in Texas, New Mexico, and Arizona.” On March 1, 1917, when the incident was recorded in the United States press and before either the State Department or the White House issued a confirmation or a denial, many congressmen and a good percentage of the United States public considered the note to be a brazen forgery and a great hoax. Had they realized that Foreign Minister Arthur Zimmermann’s proposal to Venustiano Carranza was not a bold and newly devised scheme but rather the climax of several years of intrigue with various Mexican officials and exile groups and had they been aware that the idea of restoring the territory lost in the middle of the nineteenth century was a Mexican rather than a German idea, there would have been but little reason to dispute the validity of the document in question.