Imagine, for a moment, that it is 1862 and you are Gen. George B. McClellan, commander of the Army of the Potomac, the Union’s premier fighting force. The Confederate Army, led by Robert E. Lee, has just invaded Maryland. As you’re preparing your strategy for checking Lee’s advance, a message arrives at headquarters: A corporal from Indiana has found an envelope lying in a field near enemy lines. Inside are three cigars. Oh, and a copy of Lee’s Special Order No. 191, detailing his invasion plan and revealing that the Confederate general has split his force in two, a daring move that has left his army dangerously exposed to attack. You’re George McClellan—beloved by your soldiers, tasked by your commander-in-chief with destroying Lee’s army. What do you do?
Smoke the cigars, obviously . But after that? If you answered, Attack with all possible speed, by god!, you have a lot to learn from Richard Slotkin’s The Long Road to Antietam: How the Civil War Became a Revolution. As its title suggests, the book sets out to show how the nature of the war changed during Lee’s Maryland campaign, which culminated in the famously bloody Battle of Antietam. Up until that point in the war, powerful men on both sides of the conflict believed that a negotiated peace might be hammered out. But after 3,600 Americans died fighting outside a farming village on the banks of Antietam Creek, Lincoln would issue the Emancipation Proclamation, a radical document that ended any hope of reconciliation. In the wake of Antietam, the Union would fight an all-out war of subjugation, with the goal of crushing the rebellion beneath its Yankee boot and ending the institution of slavery by force.
Slotkin, a historian and a writer of historical fiction, offers an absorbing account of this evolution. But the central figure of The Long Road to Antietam isn’t the author of the Emancipation Proclamation; it’s a man who openly opposed it—George McClellan. Vainglorious but insecure, power-hungry but risk-averse, a Democrat fighting a Republican’s war, McClellan is arguably the Civil War’s most fascinating figure and certainly its most frustrating. In McClellan, Slotkin finds an embodiment of the thinking that Lincoln repudiated with the issuing of the Emancipation Proclamation, namely the idea that the South should be compelled to rejoin the Union, but allowed to preserve its peculiar institution. Unfortunately for Lincoln, McClellan was also the Union’s best hope for delivering a battlefield victory big enough to give the president the political capital required to issue such a controversial proclamation. Reading deeply and thoughtfully through McClellan’s correspondence—the general didn’t so much as trim his moustache without first dropping a line to his wife Mary Ellen—Slotkin paints a detailed portrait of the talented but flawed general who helped Lincoln bring about his revolution, if ever so unwillingly.
So what did McClellan do when presented with the copy of Lee’s invasion plan rolled up with those cigars? He first sent a few telegraphs to his superiors crowing about how he was about to deliver a decisive victory. (To Lincoln: “I have all the plans of the Rebels and will catch them in their own trap.”) But he soon fell victim to the second thoughts that plagued him throughout his career as a commander. Though he issued orders to act on the intelligence, they exhibited, in Slotkin’s words, a “balance between boldness and anxiety,” and failed to take full advantage of his remarkable good fortune in stumbling upon his enemy’s plan. (As Slotkin notes, the discovery of Lee’s orders was pure serendipity—intelligence-gathering was among McClellan’s weaknesses.) Union forces won a minor victory on the strength of the lost plans, at the Battle of South Mountain, but failed to destroy Lee’s force, allowing him to retreat and fight another day (at Antietam, it would turn out). Despite the modesty of the South Mountain victory, McClellan reported it to his wife with typical immodesty: “If I can believe one tenth of what is reported, God has seldom given an army a greater victory than this.”
Here, as throughout the book, Slotkin is careful not to use the benefit of hindsight to judge McClellan too harshly. He isn’t convinced, as some of the general’s tougher critics have been, that had McClellan acted without anxiety his army could have decimated Lee’s at South Mountain. “It could be argued,” he writes, “that McClellan’s caution was reasonable given his estimate of enemy strength, even if it is hard for historians who know how wrong McClellan was to accept that judgment.” Partially as a result of his poor intelligence-gathering apparatus, McClellan had a tendency to wildly overestimate the size of his opponent’s army and thus miss opportunities to exploit his superior forces. At Antietam, McClellan would convince himself that he was facing down a Confederate force of 65,000 men. Slotkin figures the number was more like 36,000.
Though McClellan often seemed to be afraid of his own shadow , he could also be wildly self-assured, and The Road to Antietam captures him in all of his megalomaniacal glory. (McClellan’s nickname was “Young Napoleon,” but reading Slotkin’s book I imagined him as an unholy combination of Alvy Singer and Douglas MacArthur.) “He would come to see his elevation as providential,” writes Slotkin, “and would interpret his successes and failures as signals of God’s intentions toward the American republic. … He confided to Mary Ellen his sense that ‘by some strange operation of magic I seem to have become the power of the land.’ ” It’s self-regard so grandiose it verges on treason.