On April 6, 1917 President Woodrow Wilson took the first steps to minimize the threat from German aliens residing in the United States by issuing twelve regulations for "alien enemies," persons of enemy birth who had not completed the naturalization process. By the end of the war, twenty regulations in all were issued. The first twelve on April 6, and the remaining eight on November 16, 1917. The authority to intern was derived from these presidential proclamations and the majority of those interned in the western United States were interned under section 20.

[1] An alien enemy shall not have in his possession, at any time or place, any fire-arm, weapon or implement of war, or component part thereof, ammunition, maxim or other silencer, bomb or explosive or material used in the manufacture of explosives;
[2] An alien enemy shall not have in his possession at any time or place, or use or operate any aircraft or wireless apparatus, or any form of signalling device, or any form of cipher code, or any paper, document or book written or printed in cipher or in which there may be invisible writing.
[3] All property found in the possession of an alien enemy in violation of the foregoing regulations shall be subject to seizure by the United States;
[4] An alien enemy shall not approach or be found within one-half of a mile of any Federal or State fort, camp, arsenal, aircraft station, Government or naval vessel, navy yard, factory, or workshop for the manufacture of munitions of war or of any products for the use of the Army or Navy;
[5] An alien enemy shall not write, print, or publish any attack or threats against the Government or Congress of the United States, or either branch thereof, or against the measures or policy of the United States, or against the person or property of any person in the military, naval, or civil service of the Unites States, or of the States or Territories, or of the District of Columbia, or of the municipal governments therein;
[6] An alien enemy shall not commit or abet any hostile act against the United States, or give information, aid, or comfort to its enemies;
[7] An alien enemy shall not reside in or continue to reside in, to remain in, or enter any locality which the President may from time to time designate by Executive Order as a prohibited area in which residence by an alien enemy shall be found by him to constitute a danger to the public peace and safety of the United States, except by permit from the President and except under such limitations or restrictions as the President may prescribe;
[8] An alien enemy whom the President shall have reasonable cause to believe to be aiding or about to aid the enemy, or to be at large to the danger of the public peace or safety of the United States, or to have violated or to be about to violate any of these regulations, shall remove to any location designated by the President by Executive Order, and shall not remove from there without a permit, or shall depart from the United States if so required by the President;
[9] No alien enemy shall depart from the United States until he shall have received such permit as the President shall prescribe, or except under order of a court, judge, or justice, under Sections 4069 and 4070 of the Revised Statutes;
[10] No alien enemy shall land in or enter the United States, except under such restrictions and at such places as the President may prescribe;
[11] If necessary to prevent violations of these regulations, all alien enemies will be obliged to register;
[12] An alien enemy whom there may be reasonable cause to believe to be aiding or about to aid the enemy, or who may be at large to the danger of the public peace or safety, or who violates or attempts to violate, or of whom there is reasonable ground to believe that he is about to violate, any regulation duly promulgated by the President, or any criminal law of the United States, or of the States or Territories thereof, will be subject to summary arrest by the United States Marshal, or his deputy, or such other officer as the President shall designate, and to confinement in such penitentiary, prison, jail, military camp, or other place of detention as may be directed by the President.

[13] An alien enemy shall not approach or be found within one hundred yards of any canal; nor within one hundred yards of any wharf, pier or dock used directly by or by means of lighters by any vessels of over five hundred (500) tons gross engaged in foreign or domestic trade other than fishing; nor within one hundred yards of any warehouse, shed, elevator, railroad terminal or other terminal, storage or transfer facility adjacent to or operated in connection with any such wharf, pier or dock; and wherever the distance between any two of such wharves, piers or docks, measured along the shore line connecting them, is less than eight hundred and eighty yards, an alien enemy shall not approach or be found within one hundred yards of such shore line.
[14] Whenever the Attorney General of the United States deem it to be necessary, for the public safety and the protection of transportation, to exclude alien enemies from the vicinity of any warehouse, elevator or railroad depot, yard or terminal which is not located within any prohibited area designated by this proclamation or the proclamation of April 6th, 1917, then an alien enemy shall not approach or be found within such a distance of any such warehouse elevator, depot, yard or terminal as may be specified by the Attorney General by regulation duly made and declared by him; and the Attorney General is hereby authorized to fix, by regulations to be made and declared from time to time, the area surrounding any such warehouse, elevator, depot, yard or terminal from which he deems it necessary, for the public safety and the protection of transportation to exclude alien enemies.
[15] An alien enemy shall not, except on public ferries, be found on any ocean, bay, river or other waters within three miles of the shore line of the United States or its territorial possessions; said shore line for the purpose of this proclamation being hereby defined as the line of sea coast and the shores of all waters of the United States and its territorial possessions connected with the high seas and navigable by ocean going vessels; nor on any of the Great Lakes, their connecting waters or harbors, within the boundaries of the United States.
[16] No alien enemy shall ascend into the air in any airplane, balloon, airship, or flying machine.
[17] An alien enemy shall not enter or be found within the District of Columbia.
[18] An alien enemy shall not enter or be found within the Panama Canal Zone.
[19] All alien enemies are hereby required to register at such times and places and in such manner as may be fixed by the Attorney General of the United States and the Attorney General is hereby authorized and directed to provide, as speedily as may be practicable, for registration of all alien enemies and for the issuance of registration cards to alien enemies and to make and declare such rules and regulations as he may deem necessary for effecting such registration; and all alien enemies and all other persons are hereby required to comply with such rules and regulations; and the Attorney General in carrying out such registration, is hereby authorized to utilize such agents, agencies, officers and departments of the United States and of the several states, territories, dependencies and municipalities thereof and of the District of Columbia as he may select for the purpose, and all such agents, agencies, officers and departments are hereby granted full authority for all acts done by them in the execution of this regulation when acting by the direction of the Attorney General. After the date fixed by the Attorney General for such registration, an alien enemy shall not be found within the limits of the United States, its territories or possessions, without having his registration card on his person.

[20] An alien enemy shall not change his place of abode or occupation or otherwise travel or move from place to place without full compliance with any such regulations as the Attorney General of the United States may, from time to time, make and declare; and the Attorney General is hereby authorized to make and declare, from time to time, such regulations concerning the movements of alien enemies as he may deem necessary in the premises and for the public safety, and to provide in such regulations for monthly, weekly or other periodical report by alien enemies to federal, state or local authorities; and all alien enemies shall report at the times and places and to the authorities specified in such regulations.