Lieber Code

Prof. Francis Lieber
(Library of Congress
Prints & Photos Div.)

Apologies for a late entry that on 24 April 1863 General Orders #100 was issued, an order often referred to as the Lieber Code.

Here is a link to the Code.

I recommend to you John Fabian Witt, Lincoln's Code (Free Press 2010). (It's cheap on Amazon.)

In the closing days of 1862, just three weeks before Emancipation, the administration of Abraham Lincoln commissioned a code setting forth the laws of war for US armies. It announced standards of conduct in wartime—concerning torture, prisoners of war, civilians, spies, and slaves—that shaped the course of the Civil War. By the twentieth century, Lincoln’s code would be incorporated into the Geneva Conventions and form the basis of a new international law of war. 

In this deeply original book, John Fabian Witt tells the fascinating history of the laws of war and its eminent cast of characters—Washington, Jefferson, Franklin, Madison, and Lincoln—as they crafted the articles that would change the course of world history. Witt’s engrossing exploration of the dilemmas at the heart of the laws of war is a prehistory of our own era. Lincoln’s Code reveals that the heated controversies of twenty-first-century warfare have roots going back to the beginnings of American history. It is a compelling story of ideals under pressure and a landmark contribution to our understanding of the American experience.

The Encyclopedia Britannica entry states,

Francis Lieber, original name Franz Lieber, (born March 18, 1798, Berlin—died Oct. 2, 1872, New York City), German-born U.S. political philosopher and jurist, best known for formulating the “laws of war.” His Code for the Government of Armies in the Field (1863) subsequently served as a basis for international conventions on the conduct of warfare. Lieber was educated at the university at Jena. A liberal political activist, he was twice imprisoned under the Prussian government. He fled to England and, in 1827, immigrated to the United States. There he began to compile and edit the first edition of the Encyclopedia Americana (1829–33). He was appointed professor of history and political economics at South Carolina College (Columbia) in 1835 and joined the faculty of Columbia College, New York City, in 1857. During this period he produced two of his most important works, Manual of Political Ethics, 2 vol. (1838–39) and On Civil Liberty and Self-Government, 2 vol. (1853). In his Code for the Government of Armies, drafted for the Union Army during the U.S. Civil War, Lieber recognized the need for a systematic, institutionalized code of behaviour to mitigate the devastation of war, protect civilians, and regulate the treatment of prisoners of war.

Interestingly, the MG Albert C. Lieber U.S. Army Reserve Center is just down the road from me and all but one of the assigned units are judge advocate units.