Source: Alien Act, 25 June 1798.
SEC. 1 Be it enacted . . .That it shall be lawful for the President of the United States at any time during the continuance of this act, to order all such aliens as he shall judge dangerous to the peace and safety of the United States, or shall have reasonable grounds to suspect are concerned in any treasonable or secret machinations against the government thereof to depart out of the territory of the United States, within such time as shall be expressed in such order, which order shall be served on such alien by delivering him a copy thereof, or leaving the same at his usual abode, and returned to the office of the Secretary of State, by the marshal or other person to whom the same shall be directed. And in case any alien, so ordered to depart, shall be found at large within the United States after the time limited in such order for his departure, and not having obtained a license from the President to reside therein, or having obtained such license shall not have conformed thereto, every such alien shall, on conviction thereof, be imprisoned for a term not exceeding three years, and shall never after be admitted to become a cities of the United States.
Source: The Alien Enemies Act, July 6, 1798
Section 1: Be it enacted . . . That whenever there shall be a declared war between the United States and any foreign nation or government, or any invasion or predatory incursion shall be perpetrated, attempted, or threatened against the territory of the United States, by any foreign nation or government . . . all natives, citizens, denizens, or subjects of the hostile nation or government, being males of the age of fourteen years and upwards, who shall be within the United States, and not actually naturalized, shall be liable to be apprehended, restrained, secured and removed, as alien enemies.