In 1863, President Abraham Lincoln signed General Order No. 100, also known as The Lieber Code, dictating how the Union Forces soldiers should conduct themselves during the Civil War.

Memorandum from an unknown source discussing the United States general orders no. 100, Lieber's code of instructions for the government of armies of the United States in the field, and the international Hague Convention rules regarding war.

"Published a year before Lieber's code, this pamphlet contains several ideas that were incorporated into that work. Halleck's commission resonates with our current debates concerning the definition of 'enemy combatants' and prisoners of war. In the letter to Lieber that is reproduced as a preface Halleck states: 'The rebel authorities claim the right to send men, in the garb of peaceful citizens, to waylay and attack our troops, to burn bridges and houses, and to destroy property and persons within our lines. They demand such persons be treated as ordinary belligerents, and that when captured they have extended to them the same rights as other prisoners of war; they also threaten that if such persons be punished as marauders and spies, they will retaliate by executing our prisoners of war in their possession. I particularly request your view on these questions.'"--Lawbook Exchange.

• The "rules of warfare" and "government of the army" as they existed in the American Civil War • All 101 Articles of War as amended through June 1863 including the famous Lieber Code (General Orders No. 100), directed by President Lincoln, which expanded the laws of land warfare and General Orders No. 49 on the granting of paroles • Copious extracts from the Revised U.S. Army Regulations through June 1863 This compendium of laws and rules is a testimony to America's reverence for the rule of law as well as its high regard for "civilized" behavior on the battlefield. The Articles of War were normative rules covering military duty and punishments allowed for violations. The Lieber Code was a new and profound law for the conduct of armies in the field, to include humane treatment of prisoners and protection of property and civilians. It had a profound affect on the evolution of the laws of land warfare in use today. Army Regulations, on the other hand, dealt with the administration and management of the army-from personnel assignments to supply and recruiting operations-all three sets of rules were used by both the Union and Confederate armies. An essential reference for students, historians, writers, reenactors, and those interested in how our Civil War armies operated.