The Lieber Code (General Orders No. 100, April 24, 1863) was the military law that governed the wartime conduct of the Union Army by defining and describing command responsibility for war crimes and crimes against humanity; and the military responsibilities of the Union soldier fighting in the American Civil War (April 12, 1861 – May 26, 1865) against the Confederate States of America (February 8, 1861 – May 9, 1865).[1]
The General Orders No. 100: Instructions for the Government of the Armies of the United States in the Field (Lieber Code) were written by Franz Lieber, a German lawyer, political philosopher, and combat veteran of the Napoleonic Wars.