Rules of war are designed to keep war “civilized.” Generally these rules are concerned with two main issues. The first is how much force is appropriate. The second is what is a legitimate target for a warring army and what is not.
Before the Civil War the rules of war generally were not formally recorded. Instead, combatants were expected
To behave in accordance with established custom and their sense of fair play. During the Revolutionary War, for example, the uniforms and tactics used by British redcoats left them highly exposed to gunfire. British commanders knew this, but they did not change their approach because they had been trained to believe that this was the polite way to fight a war. During the Civil War, many officers and soldiers continued to adhere to these unwritten rules. For example, when the Confederate ordnance department developed land mines, some Confederate commanders refused to use them because they thought them ungentlemanly.
Ultimately, however, the era of polite warfare and unwritten rules had come to an end. The Civil War was a time of transition between the limited warfare of the past and the “total war” that was to become the standard in the 20th century. Recognizing this new reality, Union leaders moved to formalize the rules of war, issuing the Lieber Code in May 1863. Prepared by legal expert and professor of political science at Columbia University Francis Lieber, the Lieber Code contained a list of 157 rules governing the conduct of Union armies and soldiers in the field. The code addressed a broad variety of topics: spies, prisoners, surrenders, noncombatants, and so forth.
The Lieber Code was not a treaty, so Confederate soldiers were not subject to its conditions. It is perhaps worth asking, then, why Union leaders would willingly place such limits on their armies. In part, they were legitimately concerned with the actions of some Union soldiers and officers. Most of the men who fought in the Civil War were not professional soldiers and so had not spent their careers being taught to behave with restraint in a time of war. As the Civil War became increasingly brutal, and as participants on both sides grew increasingly desperate, there were numerous incidents of excessive violence or violence against inappropriate targets. Such incidents undermined support for the war among Northerners and among the international community, while often provoking violent retaliation from the Confederacy.
As the Lieber Code tried to limit the brutality of “total war” in some contexts, however, it also justified it in other contexts. Although the code placed “civilized” limits on what Union soldiers were allowed to do, it also provided broad discretionary powers for Union commanders to do what they deemed “necessary.” For example, Sherman’s March through Georgia in 1864 might have been unthinkable under the informal codes of conduct in place at the beginning of the war, but it was entirely justifiable under the terms of the Lieber Code.
Ultimately, the Civil War affected the rules of war in two important ways. The transition to total war continued unabated in the post-Civil War era. The Indian Wars of the 1870s were incredibly violent. The Spanish-American and Philippine Wars also had their share of brutality, and World War I may have set a standard that will never be matched in terms of the lack of restraint shown by combatants on both sides.
At the same time, while the Civil War helped to make war more violent, it also provided a precedent for trying to address that violence, as formal and comprehensive agreements about the conduct of war became an international standard. In 1864, for example, as the Civil War was still being waged, a consortium of European powers signed the Geneva Convention. The agreement, which governs the treatment of prisoners and other conduct in war, remains in effect to the present day and has been joined by a number of other international agreements about armed conflict.
See also foraging.
Further reading: Mark Grimsley, The Hard Hand of War-Union Military Policy toward Southern Civilians, 18611865 (New York: Cambridge University Press, 1995).
—Christopher Bates
World History
