Executive Order 2604—Censorship of Submarine Cables, Telegraph and Telephone Lines
Whereas, the existence of a state of war between the United States and the Imperial German Government makes it essential to the public safety that no communication of a character which would aid the enemy or its allies shall be had,
Therefore, by virtue of the power vested in me under the Constitution and by the Joint Resolution passed by Congress on April 6, 1917, declaring the existence of a state of war, it is ordered that all companies or other persons, owning, controlling or operating telegraph and telephone lines or submarine cables, are hereby prohibited from transmitting messages to points without the United States, and from delivering messages received from such points, except those permitted under rules and regulations to be established by the Secretary of War for telegraph and telephone lines, and by the Secretary of the Navy for submarine cables,
To these Departments, respectively, is delegated the duty of preparing and enforcing rules and regulations under this order to accomplish the purpose mentioned.
This order shall take effect from this date.
THE WHITE HOUSE,
April 28, 1917.
Woodrow Wilson, Executive Order 2604—Censorship of Submarine Cables, Telegraph and Telephone Lines Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/275432