Ulysses S. Grant and William T. Sherman emerged as the authentic military geniuses of the American Civil War. While the leading generals of the Confederacy still viewed warfare as an exercise in chivalric valour, these men knew that, in the modern era, war is a battle of societal wills; it is the marshalling and wielding of the sum total of a people’s manpower, infrastructure, manufacturing capacity, and morale. Grant, denigrated as a bloody butcher, and Sherman, labelled a terrorist by scorned Southerners, anticipated the military thinking of the 20th century to smash the Confederacy and, in doing so, presaged the horrors of the First and Second World Wars.
A War of Attrition
Ulysses S. Grant drew the ire of the Northern public for the casualties suffered by his Army of the Potamic in its Overland Campaign against Robert E. Lee’s Army of Northern Virginia in 1864. Branded a butcher by the press, Grant’s tactics portended the bloody arithmetic that would characterise war on the Western Front a half-century later. Grant was a general who principally favoured rapid strategic manoeuvre over bloody, front-on assaults. Grant’s Vicksburg Campaign of 1863, heralded as the finest of the era, was a masterful display of cunning, speed, and audacity, belying his historical reputation as a brute. Nonetheless, in his confrontation with Lee in the end stages of the Civil War, Grant understood that the rebel South, numerically inferior to the Union North, had few men of fighting age left to mobilise. Lee’s Army, however gallant, could no longer afford to absorb casualties. Grant opened his Overland campaign at the Battle of the Wilderness in May 1864, losing 17,666 men killed, wounded, captured, or missing to Lee’s 11,003. Grant, undeterred by losses other generals might consider calamitous, pressed on with an offensive campaign which culminated in the Battle of Cold Harbour from May 31 – June 12. At Cold Harbour, Grant ordered a front-on assault on Lee’s entrenched and fortified position, resulting in lopsided casualties – Union losses amounted to 12,738 men compared to rebel losses of 5,287. All told, the Overland campaign cost the Army of the Potamic 55,000 men (or 45% of the Army) to Lee’s 35,000 (50%). In just over eight weeks, Grant had sapped the strength of the Army of Northern Virginia, trapping it in the outskirts of Richmond and Petersburg where it would remain until shortly before Lee’s surrender in April 1865. Grant, with his ability to stomach massive losses, understood that war was fast evolving into a meat grinder, and was no longer a gentlemanly contest of strategy. Through Grant’s reliance on attritive warfare, in which the side that can replenish its ranks for longer wins out in the end, the world glimpsed the horrors that loomed in the 20th century. The Overland Campaign appears as child’s play alongside the 500,000 dead at the Battle of Passchendaele or the 1 million casualties at the Battle of the Somme. The trenches on the Western Front swallowed entire generations for causes far less noble than the American Union or the abolition of slavery. If the public thought Grant a butcher in 1864, they would shudder if they knew what was to come.
Hard War
As Grant tightened his stranglehold on Lee’s Army outside Petersburg, William Tecumseh Sherman burned and pillaged his way through Georgia and Carolina. Perhaps before any man of the era, Sherman understood the centrality of manufacturing in modern conflict, issuing this pre-war admonition to a blustering Southern colleague:
“The North can make a steam engine, locomotive, or railway car; hardly a yard of cloth or pair of shoes can you make. You are rushing into war with one of the most powerful, ingeniously mechanical, and determined people on Earth — right at your doors. You are bound to fail.”
Embodying the Union’s ‘hard war’ philosophy, Sherman, operating free from supply lines deep in enemy territory, sought to gut the Confederacy’s manufacturing sector and wreck the civilian infrastructure sustaining the war effort. All along his 459km March to the Sea from Atalanta to the Carolina coast, Sherman destroyed textile mills and factories, burned crops, repossessed telegraph line, and twisted railway tracks. He intended to smash Southern morale while depriving Confederate armies of war materiel, food, and information, rendering them impotent. The Union Army of the West inflicted $982 million (2023 equivalent) in damage to the Confederate economy, leading Southerners to label Sherman a terrorist who scorned the rules of war. In fact, he was the herald of a new era, in which cities and civilian infrastructure were to become ready targets for destruction. Sherman’s March presaged the 20th century concept of the home front and the strategic bombing campaigns of the Second World War, in which the Allies firebombed entire cities to disrupt manufacturing and rail transportation. Though his Army killed very few civilians, Sherman opined on the culpability of the Southern people and was immune to their outrage as he expelled them from captured cities. He wrote that if Southerners “want peace, they and their relatives must stop the war”. Sherman’s campaign wreaked psychological havoc in the South as he destroyed wealth and humiliated this proud martial culture by doing as he pleased in their backyard. Some 15 years later, he remained unapologetic:
“Those people made war on us, defied and dared us to come south to their country, where they boasted they would kill us and do all manner of horrible things. We accepted their challenge, and now for them to whine and complain of the natural and necessary results is beneath contempt”.
The moral and psychological elements of Sherman’s March, considered unusually callous at the time, were established military doctrine by 1942. In an attitude reminiscent of Sherman, Arthur Harris of the Royal Air Force Bomber Command said of the Germans that they “sowed the wind and now they are going to reap the whirlwind”. The whirlwind surely arrived as the air raids on Hamburg and Dresden killed a combined 60,000 people. Likewise, the American firebombing of Tokyo in 1945, which killed 300,000 civilians, was justified on the grounds that the Japanese people were sustaining the war effort through manufacturing and were thus legitimate targets. Sherman’s path of destruction represented the increasingly blurry line between civilian and military targets in modern war – a line that was to all but disappear in the great conflicts of the 20th century.
The strategies employed by these controversial men portended the nightmarish evolution of modern conflict. Grant and Sherman understood that modern warfare is not a strategic contest between small, professional armies in the field but a clash of entire societies, governed by cold, inhuman rules. The events of the 20th century would demonstrate the wisdom of their ideas and the calamitous ends to which they would lead.
You should caveat that both Sherman and Grant preferred maneuver to head-on assaults. They both regretted Kennesaw Mountain and Cold Harbor, respectively, and Sherman's campaign to Atlanta was otherwise textbook in this regard.