22 U.S.C. § 503
Whereas the United States has entered into conventions with the Governments of Uruguay, Guatemala, Salvador, Panama, and Venezuela which were signed on August 27, 1918, December 3, 1918, January 28, 1919, February 8, 1919, and July 3, 1919, respectively, for facilitating the work of traveling salesmen; and
Whereas Articles I and II of each of said conventions read as follows:
"ARTICLE I. Manufacturers, merchants, and traders domiciled within the jurisdiction of one of the high contracting parties may operate as commercial travelers either personally or by means of agents or employees within the jurisdiction of the other high contracting party on obtaining from the latter, upon payment of a single fee, a license which shall be valid throughout its entire territorial jurisdiction.
"In case either of the high contracting parties shall be engaged in war, it reserves to itself the right to prevent from operating within its jurisdiction under the provisions of this treaty, or otherwise, enemy nationals or other aliens whose presence it may consider prejudicial to public order and national safety.
"ART. II. In order to secure the license above mentioned the applicant must obtain from the country of domicile of the manufacturers, merchants, and traders represented a certificate attesting his character as commercial traveler. This certificate, which shall be issued by the authority to be designated in each country for the purpose, shall be visaed by the consul of the country in which the applicant proposes to operate, and the authorities of the latter shall, upon the presentation of such certificate, issue to the applicant the national license as provided in Article I."
Now, therefore, the Secretary of Commerce, or any person in the Department of Commerce designated by him, is authorized to issue the licenses and certificates of identification which are provided for by the said Articles I and II, respectively, of the said conventions, or which may be provided for by similar articles in any convention or treaty that may, on and after September 22, 1922, be concluded by the United States with a foreign government, and is further authorized to collect a reasonable fee for each license and certificate of identification issued. The amount of such fee shall be fixed by regulations made by the Secretary of Commerce and shall be paid into the Treasury of the United States quarterly.
22 U.S.C. § 503