Out of the august night, James Gurley came galloping past the massive oak before Elizabeth Thomas' white plantation house. Get out! he shouted. Take your family and run! Now! The renegade slave leader Nat Turner was coming with a band of vengeful slaves, rampaging from farm to farm, killing white men, women and children.

George Henry Thomas, 15, piled into a carriage with his mother and sisters and racketed along dirt roads into the darkness. Before they had gone far, afraid the assassins would overtake them, they abandoned the carriage and took to the woods. In and out of gloomy Mill Swamp, across Cypress Bridge and the bottomlands of the Nottoway River, they escaped to the county seat of Jerusalem, some 12 zigzag miles from home.

Nat Turner's 1831 insurrection, in Southampton County, Virginia, was the bloodiest slave uprising in American history. Before it ended, 55 whites were killed. It stirred deep fears across the South, sweeping aside any talk of gradual emancipation, and hardened both sides in the long-running debate that ended in civil war. What it did to young George Thomas, who as a Union general became one of the most successful, most controversial, yet least recognized figures of that war, remains a question unsettled.

While Turner and his band, armed with guns, clubs, axes and swords, carried out their gruesome task, Thomas' mother led her family to safety, helped to do so by some of her own slaves, according to local tradition. George's father had died two years earlier. The boy's uncle, James Rochelle, who had mentored him since his father's death, was clerk of the court where Turner confessed and was hanged that November. Young George was immersed in the initial panic, the mobilization of militia and the fury of citizens demanding prompt justice. He heard talk that all the trouble would never have happened if Turner had not been taught to read and write.

Teaching slaves was illegal in Virginia and across the South, but George was among the many who had broken the law, teaching his own family's 15 slaves to read.

After attending the local academy, he became his uncle's deputy clerk and took up the study of law at the county courthouse. But he was restless, and gladly accepted an appointment from his congressman to the U.S. Military Academy at West Point. He would long remember the parting advice he got from his brother John: "Having done what you conscientiously believe to be right, you may regret, but should never be annoyed by, a want of approbation on the part of others." It was advice that would prove prophetic.

Nearly six feet tall, solid in body and stubborn in temperament, George was almost 20 years old when he arrived at West Point. His roommate was a red-haired, impulsive Ohioan named William Tecumseh "Cump" Sherman. They became friendly rivals, and after four years Sherman had finished 6th, Thomas 12th, among the 42 members of the class of 1840. Along the way, Thomas put a halt to the hazing of some fellow cadets by threatening to throw a bullying upperclassman out a barracks window; after years helping supervise a sprawling plantation, he had learned to exert calm authority. Among the cadets, his gravitas earned him his first of many nicknames: Old Tom.

Five months after graduation, Thomas sailed for Florida and the long, ugly little war begun by Andrew Jackson to force the Seminole Indians onto reservations. Thomas' captain wrote an appraisal that would well describe his entire career: "I never knew him to be late or in a hurry. All his movements were deliberate, his self-possession was supreme, and he received and gave orders with equal serenity."

Real war lay ahead in Mexico, where as an artillery lieutenant under Gen. Zachary Taylor in 1846, Thomas won honorary promotion to captain for his conduct in the pitched battle of Monterrey. Then Thomas was breveted to major for the way he handled his guns at Buena Vista, when Taylor defeated Mexican general Santa Anna in the last major battle in northern Mexico.

Southampton County was proud of its son, and presented him a magnificent sword, its gold pommel clasping an amethyst, its silver scabbard engraved with the names of his battles. On its grip was the image of an elephant—among soldiers, to have been in combat was to have "seen the elephant." And Thomas was still devoted to home: disappointed that his brother had not picked a bride for him, George said, "I would prefer one from the old state to any other, and as I am now so much of a stranger there I am afraid I should not know where to look. ..." In his letters, he worried about his unmarried sisters, left lonely on the farm, saying "domestic differences are to me the most horrible of which I can conceive." He could not yet imagine the scope of the domestic differences that lay ahead.

In 1851 he headed to the prize assignment of artillery instructor at West Point. At every stop since his first arrival there, he had met and measured cadets and fellow officers who would figure in his future—Sherman, J.E.B. Stuart, John Schofield, William Rosecrans, Braxton Bragg, John Bell Hood, among dozens destined to become famous in Civil War history. None was more impressive than the superintendent of the academy, Lt. Col. Robert E. Lee, and no one there impressed Lee more positively than upright, conscientious George Thomas.

Under Lee, Thomas had the additional duty of cavalry instructor. In that role, Thomas won yet another nickname, Old Slow Trot, for restraining cadets from galloping their mounts. Since his brother had not found him a bride, Thomas found his own—tall, strong-minded Frances Kellogg, an upstate New Yorker, cousin of a cadet from Troy. He wore his ceremonial sword for the only time in his life when they were married in the academy chapel in November 1852.

Within six months, Thomas had to leave his bride for duty in the far Southwest; it would be three years before he saw her again. In a desert clash with a Comanche brave, he narrowly escaped death when an arrow glanced off his chin before lodging in his chest. Thomas pulled it out and, after a surgeon dressed the wound, went about his business. Then, in 1860, with the country in crisis after Abraham Lincoln was elected president, Thomas headed home on leave.

While there, he worried about his future as the Southern states began to secede. Governor John Letcher offered to make him Virginia's chief of ordnance. In turning that position down, Thomas wrote: "It is not my wish to leave the service of the United States as long as it is honorable for me to remain in it, and therefore as long as my native State Virginia remains in the Union it is my purpose to remain in the Army, unless required to perform duties alike repulsive to honor and humanity."

A month later, in April 1861, on the day Confederate guns opened against Fort Sumter in Charleston Harbor, Thomas sent telegrams to his wife and sisters, stating that he would remain loyal to the Union. We do not know exactly what he said then or what was going on inside him at other critical moments, because all his personal papers were destroyed. But his wife said that "whichever way he turned the matter over in his mind, his oath of allegiance to his Government always came uppermost." When Lincoln called for troops to put down the insurrection, Virginia joined the Confederacy, along with most of her professional soldiers. But Thomas stayed true to his oath, and to this day has been reviled by many Southerners for that decision.

Even his own sisters turned his picture to the wall and denied that they had any such brother. They returned his letters unopened and ignored his request to send him the ceremonial sword he had left with them for safekeeping. He also lost contact with his brothers. Some called him a turncoat.

The truth is that Thomas, like many other soldiers, was torn by the wrenching decision he was forced to make. So was his friend Lee, who opposed secession and agonized over resigning from the U.S. Army that he had served so faithfully. But Lee ultimately headed South, saying he could not bring himself to fight against his home, family and friends. It is also true that Lee had a much larger stake in Virginia, in its plantations and history, than Thomas did in his more modest place in Southampton. And besides his loyalty to the old flag, Thomas was committed to a Northern wife who was as strongly Unionist as his sisters were secessionist.

His memories of Nat Turner's insurrection might have hardened him into a determined defender of slavery, as it did for so many of the Southern officers who went with the Confederacy. Instead—perhaps remembering the eager blacks he had taught to read and write—he fought to overturn the "peculiar institution." Though he left no bold statements of how he felt, when his duty came to include ending slavery, he carried it out just as forcefully as when it stood for simply preserving the Union.

Those who protest Thomas' decision have made less of the fact that old Winfield Scott, general in chief of the Army in the early months of the war, was also a Virginian. He had been a national figure since the War of 1812, but by late 1861 he had retired and no longer mattered. Tens of thousands of Southerners fought for the Union, but Thomas has been the focus of resentment for one reason: he was a better general than the others.

As early as his cadet days, Thomas' contemporaries had seen a resemblance to George Washington in his classic profile, his integrity and his restrained power. In 48 months of war, as his brown hair and well-trimmed beard began to gray, he would attain a certain grandeur that only strengthened that comparison. He seldom showed his explosive temper, but when he did, it was remembered. He disdained theatrics and politics; to general and future president James A. Garfield, his whole life seemed "frank and guileless." Thus in character, if not in gambling instinct, he also closely resembled Lee, who was a role model for so many younger officers who served under him.

Thomas would earn the undying loyalty of soldiers like Henry Van Ness Boynton, who won the Congressional Medal of Honor fighting under him in 1863. Boynton wrote that Thomas "looked upon the lives of his soldiers as a sacred trust, not to be carelessly imperiled. Whenever he moved to battle, it was certain that everything had been done that prudence, deliberation, thought and cool judgment could do under surrounding circumstances to ensure success commensurate with the cost of the lives of men. And so it came to pass that when the war ended it could be truthfully written of Thomas alone that he never lost a movement or a battle."

But for Thomas, every battlefield success seemed to stir controversy or the jealousy of ambitious rivals. Unlike other noted generals, he had no home-state politicians to lobby on his behalf in Washington. Ulysses S. Grant, for example, was championed by Illinois congressman Elihu Washburne, and Sherman by his brother, Ohio senator John Sherman. For Thomas, every step upward depended solely on his performance in the field.

In one of the war's first skirmishes, he led a brigade in the Shenandoah Valley that bested Confederates under Stonewall Jackson. When the dashing Rebel J.E.B. Stuart heard that Thomas was commanding Union cavalry, he wrote to his wife that "I would like to hang him as a traitor to his native state." Even after that, there was lingering doubt among some Unionists, including Lincoln. Unlike Grant, Sherman, George McClellan and some other ranking Union officers who had broken their military service with years as civilians, Thomas had been a soldier since the day he entered West Point. Yet when his name came up for promotion, the president, restrained by Northern radicals and surrounded in the Federal bureaucracy by Southerners, said, "let the Virginian wait." But Sherman among others vouched for Thomas, and soon the Virginian was elevated to brigadier general and ordered to organize troops away from Virginia, beyond the Appalachians.

There, in January 1862, he sent a bulletin of encouragement to a Union hungry for good news. After an 18-day march on muddy roads, his division confronted Rebels at Mill Springs, Kentucky. Amid cold rain and gun smoke, he led his outnumbered troops in repulsing Confederates under Maj. Gen. George Crittenden and then drove them across the Cumberland River. Though not a massive victory, it was the first notable Northern success of the war, turning back a Confederate move from eastern Tennessee into Kentucky. Thomas was promoted to major general, an advancement that would soon create friction with his old roommate "Cump" Sherman and Grant, who had become so close that an affront to either was resented by both.

After winning praise for capturing Forts Henry and Donelson in western Tennessee, Grant had fallen out of favor for mismanaging and very nearly losing the bloody Battle of Shiloh. He was criticized for taking 13,000 casualties and was suspected of drinking on the job. Sherman, whose excitability and wild overestimates of Rebel strength had caused some to question his sanity, had fought bravely after an initial mistake at Shiloh. When Union forces moved south toward Corinth, Mississippi, that spring, Union general Henry Halleck shunted Grant into a figurehead role and gave Thomas temporary command of the wing that included Grant's Army of the Tennessee. Grant, angered, was talked out of quitting by Sherman. Grant would not forget the incident.

Grant and Sherman would redeem themselves by grasping control of the Mississippi River in the costly, circuitous campaign that resulted in the capture of Vicksburg in mid-1863. While they were operating on the Mississippi, Thomas led a corps in Rosecrans' Army of the Cumberland, earning respect in fights like that at Stones River, where he declared, "This army does not retreat," and backed up his words with actions on the field. There and at Tullahoma, Rosecrans' force pressed the Confederates back into eastern Tennessee.

As Thomas rose, he proved to his men that his addiction to detail and his insistence on preparation saved lives and won battles. His generalship behind the front, before the battle, was generations ahead of his peers. He organized a professional headquarters that made other generals' staff work seem haphazard. His mess and hospital services, his maps and his scouting network were all models of efficiency; he was never surprised as Grant had been at Shiloh. He anticipated modern warfare with his emphasis on logistics, rapidly repairing his railroad supply lines and teaching his soldiers that a battle could turn on the broken linchpin of a cannon. He demanded by-the-book discipline, but taught it by example. He made no ringing pronouncements to the press. His troops came to understand his fatherly concern for their welfare, and when they met the enemy they had faith in his orders.

In late summer, Rosecrans moved against the Rebel stronghold of Chattanooga, a crucial gateway between the eastern and western theaters of war. Confederate general Bragg pulled out of the town onto the dominating nearby mountains, waiting for Maj. Gen. James Longstreet to bring reinforcements from Virginia. When they came, Bragg threw everything into an assault on Union lines along Chickamauga Creek, just inside Georgia. Thomas' corps was dug in on the Union left. On the second day of furious fighting, a misunderstood order opened a wide gap on his right. Longstreet's Rebels crashed through; with the always aggressive John Bell Hood's division leading, they bent the Union line into a horseshoe.

Rosecrans, certain the battle was lost, retreated into Chattanooga with five other generals and thousands of blue-uniformed soldiers. But Thomas inspired his men to stand fast, and only their determined resistance saved his army from destruction. They held all that afternoon against repeated Confederate assaults, withdrawing into Chattanooga after nightfall. It was the greatest of all battles in the West, and since that day, Thomas has been known to history as the Rock of Chickamauga.

For their actions, Rosecrans was fired and Thomas took command of the Army of the Cumberland. But the Union situation remained dire. Bragg, still holding those formidable mountains, laid siege to Chattanooga. Grant, commanding Union armies between the Mississippi and the mountains, ordered Thomas to hold the city "at all costs," and rushed troops east to help.

"I will hold the town till we starve," Thomas replied, and they almost did starve. Cut off from supplies, his army was living on half rations. Thousands of horses and mules died. Weeks passed before Grant assembled strength sufficient to lift the siege. The key terrain was towering Missionary Ridge. Grant ordered Sherman to drive onto the ridge from the left and Maj. Gen. Joseph Hooker from the right, with Thomas aimed at the center. Sherman tried and failed to carry his end, but Hooker's troops took Lookout Mountain on the far flank. Thomas waited for Grant's order to advance. When it came, Thomas took his time studying the crest with his binoculars, then sent his troops ahead with orders to occupy only the first line of the Confederate works. They did so in fine style—and then, seeing that they were exposed to fire from above, kept going. Thomas was surprised and Grant angry, demanding "Who ordered those men up the hill?" No one had. The troops plunged ahead, pressing on against heavy fire, struggling up the steep slope and jubilantly planting their flag on the heights for all to see.

Assistant Secretary of War Charles A. Dana, an eyewitness, called the assault "one of the greatest miracles in military history....as awful as a visible interposition of God." Thomas, moved by the sight, ordered that a cemetery be created for his soldiers on a beautiful slope of the battlefield. When a chaplain asked if the dead should be separated by state, Thomas did not hesitate. "No, no," he said. "Mix them up. Mix them up. I'm tired of states' rights." Once he had made up his mind to stay with the old flag, he never expressed misgivings; if he had them, they had long been erased by seeing so many men die to preserve the Union.

By late 1883, U.S. Colored Troops were filling some of the gaps opened in Federal forces by battle and disease. Although Sherman had resisted using black soldiers, Thomas gladly accepted them. In the drastic move from serfdom to freedom, he wrote, it was probably better for ex-slaves to be soldiers, and thus gradually learn to support themselves, than "to be thrown upon the cold charities of the world without sympathy or assistance."

As the Federals gathered strength to thrust into Georgia, this was not the only disagreement between the tightly strung Ohioan and the calm Virginian. In early March, Lincoln called Grant east to become general in chief of all Northern armies. No one was surprised that Grant's friend Sherman, rather than Thomas, replaced him as commander in the West, even though as a major general Thomas was senior to Sherman. Ex-colonel Donn Piatt, a 19th-century booster and biographer of Thomas, called it "the nakedest favoritism that ever disgraced a service."

At the start of his 1864 drive toward Atlanta, Sherman rejected Thomas' plan to take his command through Snake Creek Gap to cut off and smash Joseph Johnston's Confederate army. More than a month into Georgia, an impatient Sherman complained to Grant that Thomas' Army of the Cumberland was slowing his advance—"a fresh furrow in a plowed field will stop the whole column." He was still in this mood a few days later when he ignored Thomas' advice against attacking the strongly entrenched Rebels head-on at Kennesaw Mountain. The Federals lost more than 2,000 troops in trying to take what Thomas had warned was an impregnable position.

Thomas commanded about two-thirds of Sherman's infantry; his army was the center force, the sledgehammer in the four-month campaign, and led the way into Atlanta. But neither Sherman, Grant, Secretary of War Edwin Stanton nor Lincoln cited Thomas in their congratulations. As in the 1864 Virginia campaign, where all the official praise and headlines went to Grant, in Georgia it was all Sherman. In his special order announcing the victory, Sherman credited Maj. Gen. Henry W. Slocum's corps with entering the city first—although Slocum was under Thomas' command and had headed the corps for only six days.

When Atlanta's mayor protested Sherman's harsh military rule, the general replied, "War is cruelty and you cannot refine it...those who brought war into our country deserve all the curses and maledictions a people can pour out....You might as well appeal against the thunderstorm." Then he set out on his storied march to infamy and greatness, pillaging the countryside as he cut a great swath through the Confederacy.

Thomas took a different view. Stern though he was in combat, he posted a guard at the house of a citizen suspected of disloyalty because, he said, "We must remember that this is a civil war, fought to preserve the Union that is based on brotherly love and patriotic belief in the one nation....The thing becomes horribly grotesque...when we visit on helpless old men, women, and children the horrors of a barbarous war. We must be as considerate and kind as possible, or we will find that in destroying the rebels we have destroyed the Union."

Opposite in personality, tactics and philosophy, Thomas and Sherman were thereafter gratefully separated in geography as well. While Grant grappled with Lee in Virginia and Sherman gutted the eastern Confederacy, Thomas was sent back to Tennessee to reorganize the stripped-down Army of the Cumberland and deal with Hood. The Confederate general had got away from Atlanta with some 40,000 troops and evaded Sherman's effort to catch him. Now he was marching north through Tennessee. Thomas' Federals under John Schofield slowed and badly damaged the Rebels in the fierce battle of Franklin, but by December Hood was dug in on the high ground facing Nashville. Thomas fortified the city while he gathered strength for a decisive blow, but to carry it out he needed more men, horses and supplies.

Grant, 500 miles away, grew impatient. He sent telegrams urging Thomas to move, then ordered him to "attack at once." Thomas said after the war that he was tempted—"grossly improper as it would have been"—to ask why Grant himself, who was entrenched around Petersburg, was not fighting. Defeat at Nashville "would have been a greater calamity than any which had befallen the Federal forces," he said. "It would have cleared the way for the triumphant march of Hood's army through Kentucky, and a successful invasion of Indiana and Illinois, in which there were no Federal troops. It was therefore of the last importance that the battle upon which so much depended should not be fought until I was ready for it." Thomas continued planning, training, stocking—equipping his horsemen with the new breech-loading Spencer carbines.

Then, just when he was ready, a sleet storm froze both armies in place for days. Grant, furious that Thomas had failed to engage the enemy, decided to relieve him from command, first with one general, then another. Finally he started to go west to fire him in person. But before he left Washington, the ice melted in middle Tennessee.

On December 15, Thomas, unaware that Grant intended to fire him, roared out of his works against Hood. In two days his troops crushed the Rebel army. His infantry, including two brigades of U.S. Colored Troops, smashed into Hood's troops while the Union cavalry, dismounted with its fast-firing Spencers, curled around and behind the Rebel left. Almost a century later, historian Bruce Catton summed up the battle in two words: "Everything worked."

Thomas "comes down in history...as the great defensive fighter, the man who could never be driven away but who was not much on the offensive. That may be a correct appraisal," wrote Catton, an admirer and biographer of Grant. "Yet it may also be worth making note that just twice in all the war was a major Confederate army driven away from a prepared position in complete rout—at Chattanooga and at Nashville. Each time the blow that finally routed it was launched by Thomas."

Nashville was the only engagement in which one army virtually annihilated another. Thomas B. Buell, a student of Civil War generalship, wrote that in Tennessee, Thomas performed the war's "unsurpassed masterpiece of theater command and control....So modern in concept, so sweeping in scope, it would become a model for strategic maneuver in 20th-century warfare." After it, there was no more large-scale fighting west of the Blue Ridge.

When the bloodshed was over at last, after Lincoln was assassinated and the nation was recovering from the shock, 150,000 soldiers of all the Union armies converged on Washington for the most memorable victory parade in the nation's history. All of them, that is, except the Army of the Cumberland. When Sherman proudly passed in review before Grant, President Andrew Johnson and multitudes of cheering onlookers, Thomas had already said goodbye to his few remaining troops. Back in Nashville, in a message that his innate reserve did not let him utter in person, he described his thoughts as he watched their last parade:

"The coldest heart must have warmed" at seeing the men who had endured "this great, modern tragedy," he wrote—men "who had stemmed with unyielding breasts the rebel tide threatening to engulph the landmarks of freedom, and who, bearing on their bronzed and furrowed brows the ennobling marks of the years of hardship, suffering and privation, undergone in defense of freedom and the integrity of the Union, could still preserve the light step and wear the cheerful expressions of youth."

Thomas' own youth was long behind him. In four years of hard service, he had taken not a single day of leave. During Reconstruction, he commanded troops in Kentucky, Tennessee, Mississippi, Alabama and Georgia. He was considerate toward ragged defeated soldiers, but he was as strict as the angriest Northern Radical in opposing the Ku Klux Klan and defiant politicians. "Everywhere in the states lately in rebellion, treason is respectable and loyalty odious," he said. "This, the people of the United States, who ended the rebellion and saved the country, will not permit."

When President Johnson wanted to make him a full general, Thomas declined, understanding the move as Johnson's attempt to sidetrack Grant's progress toward the White House. He said he had done nothing since the war to deserve promotion, and if the honor was for wartime service, it had come too late. When he heard talk of nominating him for president, he staunched that too. So Grant was duly elected, in 1868, and soon afterward transferred Thomas to San Francisco. There, in 1870 at the age of 53, the Rock of Chickamauga suffered a stroke and died.

The train bearing his body crossed the country to his wife's hometown of Troy, New York, with troops firing salutes along the way. President Grant and General in Chief Sherman, putting aside for the moment their criticism of Thomas, led the throng of mourners at the funeral. But no one was there from the Thomas family of Southampton County. Shortly after Lee's surrender, Union general John Gibbon had heard that the Thomas sisters were suffering, and sent them a wagonload of supplies as a token of his friendship for their brother. Judith Thomas would not accept, insisting she had no brother George, that he had died on the day Virginia seceded.

In 1879, veterans of the Army of the Cumberland dedicated an equestrian statue of Southampton's most distinguished son in Washington's Thomas Circle. He peers down 14th Street toward Virginia today, as dense traffic runs around him; perhaps one passerby in a thousand knows who he is and what he did for the nation.

After Thomas died, Grant was able to say that he was "one of the great names of our history, one of the greatest heroes of our war." Sherman relented so far as to write that "during the whole war his services were transcendent." Yet even then, the two generals seldom mentioned his name without repeating their assertions of his caution. When the two surviving Thomas sisters were nearing 90, they allowed the general's prize sword to go to the Virginia Historical Society in Richmond, where it remains. As a further gesture of reconciliation, they sent acorns from the great oak outside the home place to be planted around his statue in Washington.

The acorns never sprouted.

Ernest B. "Pat" Furgurson is the author of Freedom Rising and other Civil War books. He lives in Washington, D.C.