The seaman presented perhaps the most perplexing problem in the control of travel. He rarely remains on the same vessel for more than a few voyages and he seldom has a real home where his antecedents can be looked up. Moreover, under the Seaman’s Act, he is permitted, if not, indeed, encouraged, to desert in an American port in order to be re-engaged at the higher American rates of pay. So long as seamen from neutral countries, particularly those adjacent to Germany, could come ashore at will in American ports, no really effective control was possible. So, following the example of England and the advice of our military attachés in the countries of northern Europe, an order was issued by the Secretary of State—though not until seventeen days before the signing of the Armistice—forbidding seamen from neutral countries to leave their ships while in American ports. The presence of naval guards on the vessels insured the enforcement of the order, which was withdrawn, however, shortly after the signing of the Armistice. By an arrangement with the State Department, all passport applications, both from citizens and aliens, are referred to M I 11 for investigation. The files of the Military Intelligence Division now contain a vast amount of information, much of it of a very detailed character, concerning persons and business firms in the United States and foreign countries. By referring to these files, therefore, or by directing its agents to make special investigations, it is an easy matter for the Passport Section to decide whether the applicant is the sort of a person to whom a passport should be granted. The passenger-list of every vessel bound for an American port is cabled to the Passport Section by the American consul upon the departure of the vessel from the last port of call. These lists are checked in the suspect files of the Military Intelligence Division, and if there is found anything which makes a passenger objectionable or suspicious, the intelligence officer at the port where the ship will arrive is promptly notified, whereupon the passenger in question is either denied entry to the United States or placed under arrest, according to his nationality and other circumstances. A somewhat similar system of control is in operation along the Mexican and Canadian borders, the immigration and intelligence officers who are stationed in the towns along the international boundaries making it difficult, though by no means impossible, for undesirables to enter or leave the country. It will thus be seen that the Passport Section, aided by a small army of military attachés, consuls, customs officials, immigration officers, secret agents, and intelligence police, has succeeded in establishing a highly effective control of travel, thus preventing the entry or departure of persons whose expressions or actions might prove detrimental to the interests of the United States.