General Orders No. 100 : The Lieber Code

INSTRUCTIONS FOR THE GOVERNMENT OF ARMIES OF THE UNITED STATES IN THE FIELD

Prepared by Francis Lieber, promulgated as General Orders No. 100 by President Lincoln, 24 April 1863.

Instructions for the Government of Armies of the United States in the Field, prepared by Francis Lieber, LL.D., Originally Issued as General Orders No. 100, Adjutant General's Office, 1863, Washington 1898: Government Printing Office.

https://avalon.law.yale.edu/19th_century/lieber.asp#sec10

Art. 82.

Men, or squads of men, who commit hostilities, whether by fighting, or inroads for destruction or plunder, or by raids of any kind, without commission, without being part and portion of the organized hostile army, and without sharing continuously in the war, but who do so with intermitting returns to their homes and avocations, or with the occasional assumption of the semblance of peaceful pursuits, divesting themselves of the character or appearance of soldiers - such men, or squads of men, are not public enemies, and, therefore, if captured, are not entitled to the privileges of prisoners of war, but shall be treated summarily as highway robbers or pirates.

Art. 83.

Scouts, or single soldiers, if disguised in the dress of the country or in the uniform of the army hostile to their own, employed in obtaining information, if found within or lurking about the lines of the captor, are treated as spies, and suffer death.

Art. 157.

Armed or unarmed resistance by citizens of the United States against the lawful movements of their troops is levying war against the United States, and is therefore treason.