Nearly two years into the war, Lincoln’s government announced “General Orders No. 100,” the rules under his armies would conduct their operations. Selected to write the code was Prussian emigre Francis Lieber, a fervent nationalist in Prussia who fled his country while under police investigation in 1825 for plotting to overthrow the government. After short residence in England, he was recruited to teach at Columbia University, and in the United States “directed the ardent nationalistic emotion with which he had regarded Germany.” Lieber believed he left behind the “bureaucratic ministries and police spies,” though his new employer relied on these as well.
Lieber’s Puzzling Code of War
“But there is a puzzling side to this document that has gone largely unnoticed by historians and legal scholars. Why was it allowed to be created and adopted? One could argue that the process by which Lieber’s code of war came into being contradicted constitutional principles and the established practices of the United States.
The Constitution states that the power to declare war and, even more pertinently, to “make rules for the government and regulation of the land and naval forces” belongs with the Congress. When the [United States] created the Articles of War in 1806, it did so through congressional legislation, not executive fiat. With General Orders No. 100, the executive branch took a bolder step than many have realized, by assuming the right to determine the parameters of war making, especially the meaning of “military necessity,” without these policies originating with Congress.
As the compilation of military law and usages made its way through the bureaucracy, Lieber understood that at least a few paragraphs might benefit from “the assistance of Congress,” but added that it “is now too late.”
[Some] sections gave the executive and his generals broad powers. The instructions allowed for the bombardment of civilians feeling a siege back into towns so their suffering could force surrender more quickly; and for taking most of the property from an enemy based on military necessity.”
(With Malice Toward Some: Treason and Loyalty in the Civil War Era, William A. Blair, UNC Press, 2014, excerpt. pp. 93-94)