Francis Lieber, Slavery, And the "Genesis" of the Laws of war‪.‬

ON APRIL 24, 1863, SECRETARY OF WAR EDWIN M. STANTON, WITH THE approval of President Abraham Lincoln, directed that General Orders No. 100: Instructions for the Government of Armies of the United States in the Field be issued to Union officers. General Orders No. 100 was the first modern codification of the rules of warfare, the first such code to be formally adopted by a government, and the basis of several subsequent editions of the standard manual governing U.S. armies in the field. The author of No. 100 was the Prussian immigrant intellectual Francis Lieber (1798-1872); it is therefore often referred to as Lieber's code. (1) Lieber himself developed a great sense of pride in the document, and in later years he referred to it as "Old Hundred." Lieber composed the code during the most intense emotional crisis of his life, and, as will be argued below, that crisis--the death of his beloved eldest son, Oscar, of the Second Regiment, South Carolina Volunteers, at the battle of Williamsburg in May 1862--left traces on the subsequent document that established the modern rules of war. The literature on Lieber's code, while not vast in scope, is high in quality. (2) Several authors have directed attention to the origins of the code, citing the military situation of 1862, the problems arising out of the use of guerrilla tactics by Confederate sympathizers, and Lieber's own desires and ambitions as a scholar of international law. However, such accounts, valid as they may be if considered in a strictly military context, must be seen as partial explanations at best, for they take no notice of a factor that Lieber himself considered to be far more important than those purely tactical problems. That factor appears in the account given directly by Lieber himself, in a letter to a once well-known, now forgotten historian that is in the Lieber papers in the Library of Congress and that no previous scholar has referred to, or presumably examined. (3) In the letter, Lieber unequivocally asserted that the code arose out of a mighty force that no code or policy had foreseen, namely the self-emancipation of scores, then hundreds, and finally thousands of slaves.