The Lieber Code (General Orders No. 100, 24 April 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 the American Civil War (1861–1864) against the Confederate States of America. 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. History Background At military age, the jurist Franz Lieber soldiered and fought in two wars, first for Prussia in the Napoleonic Wars (1803–1815) and then for the Greek War of Independence (1821) from the Ottoman Empire (1299–1922). In his later career, Lieber was an academic at the College of South Carolina, in the Confederate States of America. Although not personally an abolitionist, Lieber opposed slavery in principle and in practise for having witnessed the brutalities of black chattel slavery in the Confederacy, from which he departed for New York City in 1857. In 1860, Prof. Lieber taught history and political science at the Columbia Law School, and publicly lectured about the “Laws and Usages of War” proposing that the laws of war correspond to a legitimate purpose for the war. In that time, Lieber had three sons who soldiered in the American Civil War (1861–1865); two sons in the Union Army, and one son in the Confederate Army, who was killed in the Battle of Eltham's Landing (7 May 1862). Later in 1862, in St. Louis, Missouri, whilst searching for the Union-soldier son wounded at the Battle of Fort Donelson (11–16 February 1862), Lieber asked the help of his professional acquaintance Major General Henry W. Halleck, who had been a lawyer before the civil war, and was author of International Law, or, Rules Regulating the Intercourse of States in Peace and War (1861) a book of political philosophy that emphasized legal correspondence between the casus belli and the purpose of the war. Legal dilemma In fighting the Army, the guerrillas, and the enemy-civilian collaborators of the Confederacy, Union Army soldiers and officers faced ethical dilemmas of command responsibility concerning their summary execution in situ, per military custom, because the 1806 Articles of War did not address the management and disposition of prisoners of war and irregular