On the evening of the first day of the Battle of Shiloh in April 1862, the Union forces at Pittsburgh Landing reflected the partial rout that had been suffered. As reinforcements were ferried across the Tennessee River, they confronted thousands of Union deserters and shirkers cowering on the riverbank.

None of this fazed Union commander ­General Ulysses S. Grant, as Ron Chernow ­details in his outstanding biography, Grant:

Wrapped in his greatcoat, Grant returned to the haven of the nearby oak tree with its spreading canopy of branches. [General William Tecumseh] Sherman found him standing there, streaming with rain, hat pulled low over his face, collar upturned, holding a lantern and chewing a cigar. “Well, Grant, we’ve had the devil’s own day, haven’t we?” Sherman remarked. “Yes,” replied Grant with a drag on his cigar. “Lick ’em tomorrow though.” The statement expressed Grant’s intestinal fortitude which communicated itself to his officers. He had already told Sherman that when both sides seem defeated in battle, the first to assume the offensive would surely win.

This encounter says much about Grant’s leadership during the terrible violence of the American Civil War. While horrified by the ­carnage he witnessed, and more than once under direct Confederate fire, including at ­Shiloh, Grant never wavered in his determination to crush the rebellion by destroying the Confederate armies and their industrial base.

The relationship with Sherman was pivotal in Grant’s ultimate success as commander of all Union armies, from August 1864. Sherman agreed it was necessary to destroy the Confederacy’s capacity to support its armies in the field. This led to Sherman’s armies pursuing a scorched-earth policy between Atlanta and Savannah, burning a 60km swathe across ­Georgia and then north into the Carolinas.

It was Grant’s success in the western theatre of the Civil War, from Fort Donelson (Tennessee), where he earned the nickname ‘‘Unconditional Surrender’’ for his refusal to discuss terms with the Confederates, to ­Vicksburg (Mississippi), where the war was ­decided by a combination of Grant’s armies and the Union navy. Taking the rebel stronghold meant reopening the Mississippi River to the embattled Republic while simultaneously cutting the Confederacy in half.

Abraham Lincoln wanted generals who would fight. Grant would not only fight, he would destroy his opponents utterly. Grant’s critics encountered a president who was unwavering in his support. One famous story holds that a group of congressmen complained to Lincoln, after the Confederate army of ­Mississippi had surrendered at Vicksburg, that Grant had been drunk for much of the siege.

Lincoln asked the politicians if they knew which brand of whiskey Grant had imbibed. They undertook to inform the president of this detail, for which Lincoln expressed satisfaction. “Very good, gentlemen, because I intend to ­dispatch a case of this whiskey to all of my ­generals. I cannot spare this man. He fights.” (Grant’s favourite whiskey was Old Crow, a Kentucky bourbon.)

Nothing in Grant’s early life suggested greatness, either in uniform or in the White House. Indeed, his fondness for the bottle did lead to his pre-war resignation from the army at Fort Humboldt, California, in April 1854, when he ­arrived for duty while intoxicated.

Before the war, his life was in something of a cul-de-sac. While his marriage to Julia Dent was loving, his career prospects were less than promising. ­Marooned in the family’s leather goods store in Galena, Illinois, which was owned by his father, Jesse, and managed by his brother Simpson, Grant would have been ­unknown were it not for the outbreak of the Civil War following Lincoln’s election in ­November 1860, and the secession of 11 southern states over the weeks that followed.

Grant was not politically active. Indeed, in 1856 he voted for James Buchanan, the Democratic nominee for president. He wanted to ­prevent the Republic splitting. Yet by early 1861, Unionists were left with no choice. Endorsed by a local congressman, Grant returned to the army to assume command of Illinois troops being raised to defeat the rebellion.

Grant had served in the Mexican War along with future opposing commander Robert E. Lee. His record was competent but in 1861 no one ­believed it would be Grant who accepted Lee’s ­surrender at Appomattox Court House, Virginia, in April 1865. And it is Appomattox that speaks most profoundly about Grant’s character in war.

He was generous to the defeated foe, writing in his memoirs:

General Lee, after all was completed and before taking leave, remarked that his army was in a very bad condition for want of food, and that they were without forage; that his men had been living for some days on parched corn exclusively, and that he would have to ask me for rations and forage. I told him ‘‘certainly’’, and asked for how many men he wanted rations. His answer was “about twenty-five thousand”: and I authorised him to send his own commissary and quartermaster to Appomattox Station, two or three miles away, where he could have, out of the trains we had stopped, all the provisions he wanted.

None of this is to deny Grant’s critics lacked foundation in attacking him for the ­terrible slaughter in The Wilderness in 1864, especially the Battle of Cold Harbor, but this was his strategy. Remorselessly wearing down the enemy, as did Sherman in the deep south and Philip Sheridan in the Shenandoah Valley, Grant’s wartime success and continuing popularity made him a certainty for the Republican nomination for president in 1872, following the disastrous and divisive term of Andrew Johnson.

Grant had a poor relationship with Johnson, whose speaking tour of northern states in the late summer of 1866 generated attacks on his political opponents that, according to senator John Sherman (Republican, Ohio), the ­general’s brother, had “sunk the presidential office to the level of a grog house”. Is there an echo here?

Chernow, the author of the brilliant Alexander Hamilton, has written a meticulously ­researched and finely balanced biography of the 18th president of the US. Most presidents undergo a revision of their terms in office and appear much better and more effective with the passage of time. This is certainly true of 20th-century presidents Harry Truman and Ronald Reagan. Chernow has contributed mightily to a reassessment of Grant, whose Civil War record was often underrated by critics and whose administration was dismissed because of totemic episodes of corruption, some involving members of his family.

Chernow is a first-class biographer, having won a Pulitzer for George Washington: A Life. Alexander Hamilton won the George Washington Book Prize, and has been turned into a ­remarkable Broadway musical.

Impressive as Chernow’s assessment happens to be, respect for Grant can only be reinforced by reading his biography in parallel with The Personal Memoirs of Ulysses S. Grant. This is the best presidential memoir written, once earning praise from no less than Mark Twain.

Chernow, too, refers to Grant’s memoir as a literary masterpiece. This remarkable accomplishment was all the more marked for having been written while suffering throat and tongue cancer, a result of heavy cigar smoking, and being in constant, severe pain. It was as much a triumph as any of his battlefield victories.

Grant wrote in a clear and logical style, much as he issued orders, which brings the day-to-day challenges and tremors of war to his readership with never a suggestion of embellishment.

He was generous to his fellow Union commanders and occasionally to his Confederate foes. On the policy of destroying the south’s ­industrial capacity, he wrote, “Their destruction was accomplished without bloodshed and ­tended to the same result as the destruction of armies. I continued this policy to the close of the war …”

As president after 1872, Grant’s administration was badly stained by corruption, with scandals such as the “Whiskey Ring” of ­organised tax evasion reaching his trusted ­associates General John McDonald in St Louis and his personal aide Colonel Orville Babcock. The “Indian Ring”, involving corrupt dealings and fraud that served to exploit Native Americans, tarnished not only interior secretary ­Columbus Delano but Grant’s brother Orvil, who was slipping perceptibly into madness.

Yet Grant’s personal standing was not ­diminished. Chernow writes: “Despite the ­scandals that had rocked his administration, Grant’s wartime heroism clung to him like an honoured, if somewhat faded, old cloak and the American public retained faith in his personal integrity.”

On the positive side, Grant’s record on emancipation, including confronting the Ku Klux Klan in the south, was admirable. Chernow quotes the great civil rights leader Frederick Douglass, who concluded that Grant had made the African-American freeman a citizen.

Grant’s record as an American Caesar is confirmed by both these books. Moreover, Chernow establishes that, as president, Grant endeavoured to continue to serve the US ­honestly and well, despite some of those close to him being seriously compromised.

He was a man to be trusted in office and he faithfully recorded a memoir that remains gripping to this day.

By Ron Chernow
Head of Zeus

The Personal Memoirs of Ulysses S. Grant: The Complete Annotated Edition
Edited by John F. Marszalek
Preface by Frank J. Williams
Harvard University Press