Your reference to chapter 10, "Amateurs Go to War," of James McPherson's seminal history of the American Civil War gets to the heart of a major problem plaguing both sides during the Civil War: although a cadre of experienced officers existed on both sides, the numbers required to fight the...
Your reference to chapter 10, "Amateurs Go to War," of James McPherson's seminal history of the American Civil War gets to the heart of a major problem plaguing both sides during the Civil War: although a cadre of experienced officers existed on both sides, the numbers required to fight the war dictated that both officers and enlisted men on both sides must be drawn from civilian life—that is, often highly motivated rank-and-file soldiers who knew little or nothing about fighting a war, especially a war in which technology far outpaced battle tactics.
As amateurs, the average soldiers enlisting to fight, both in the North and South, had no conception of the carnage that awaited them:
Expecting a short and glorious war, southern boys rushed to join the colors before the fun was over. ... Even those that made a pretense of practicing military maneuvers sometimes resembled drum and bugle corps more than fighting units. (317)
The rank-and-file soldiers on both sides often viewed the war as a chance to get some diversion and excitement in their lives and treated military discipline with disdain. As citizen soldiers, they consistently retained a view that military life should be viewed as an interesting experience but not something that required strict adherence to rules.
In the North, as well, both civil and military leaders believed that the war will be over in a matter of months, and, to the extent that they planned anything, their estimates of what numbers of troops and supplies they need were laughably low. Even the experienced officers planning campaigns were planning to fight their last war, the Mexican-American War of two decades in the past.
As McPherson points out, at the outbreak of hostilities in 1861, the Federal "army had nothing resembling a general staff, no strategic plans, no program for mobilization" (313). More important, however, was the lack of experienced officers:
Only two officers had commanded as much as a brigade [about 4,000 men] in battle, and both were over seventy. (313)
The lack of experienced officers left the Federal authorities no choice but to place well-connected civilians into the officer corps in large numbers simply in order to field sufficient troops to fight a battle. Most of these men not only had no experience in military life but were manifestly unsuited to lead other amateurs into battle, a circumstance that often resulted in casualty rates that stagger a modern conception of acceptable losses. During the Battle of Antietam (Sharpsburg) in 1862, a twelve-hour battle, both sides suffered approximately 23,000 casualties and 3,600 dead, and much of this carnage was the result of wretched leadership decisions implemented poorly by citizen soldiers and their officers. This battle exemplifies, more than any other, the cost in human suffering created by fighting a war with amateurs who led and those who followed.
Even though the Confederacy had a higher number of men with military experience, especially in the officer corps, both the South and the North were forced to rely on amateur troops throughout the war because the casualty rates among troops was so horrendous, even when they were not fighting, that there were simply not enough men to sustain a struggle.
The average officer and soldier on both sides learned their trade through on-the-job experience, and many died or were killed before they could come up the learning curve.