From Grant, by Ron Chernow (Penguin, 2018), Kindle pp. 148-152:
Grant needed a commanding personality to manage his office and ride herd over his staff and from the outset selected John Rawlins for a special place in his entourage. Rawlins was the pallid young lawyer with the full dark beard, saturnine aura, and enormous dark eyes who had bowled over Grant with his impassioned oratory at the Galena recruiting meeting. On August 30, Rawlins was appointed assistant adjutant general with the rank of captain, effectively making him Grant’s chief of staff. With no military background, he was startled that Grant gave him such a high appointment.
Rawlins’s family history with alcohol abuse gave him a special purchase on Grant’s drinking troubles, making it an all-consuming preoccupation. Before joining his staff, he extracted a pledge from Grant that he would not touch a drop of liquor until the war ended, and he would monitor this vow with Old Testament fervor, carrying on a lonely, one-man crusade to keep Grant sober. That Grant agreed to this deal shows his strong willingness to confront his drinking problem. The mission perfectly suited Rawlins’s zealous nature. With Grant’s consent, he laid down draconian rules to curb drinking, forbidding the open use of liquor at headquarters. In general orders that announced Rawlins’s appointment, Grant berated men who “visit together the lowest drinking and dancing saloons; quarrel, curse, drink and carouse . . . Such conduct is totally subversive of good order and Military Discipline and must be discontinued.” With Rawlins on the premises, even senior officers drank secretly in their tents. Any staff member who furnished Grant with alcohol faced the fervid wrath of Rawlins and likely dismissal. Rawlins fretted over Grant, agonizing over suspected lapses from the straight path of abstinence. He had no compunctions about chastising Grant for lapses, and his unflagging vigilance was remarkable in its forthright passion and candor.
Grant never discussed publicly his drinking pact with Rawlins, but he must have taken it to heart since Rawlins became his right-hand man and alter ego during the war. He allowed Rawlins to be the moralistic scourge and resident conscience of his staff. Later in the war, Grant wrote that Rawlins “comes the nearest being indispensable to me of any officer in the service.” In entering the army and assuming tremendous responsibilities, Grant must have feared he would be hurled back into the hard-drinking world of officers from which he fled in 1854, endangering the hard-earned sobriety of his St. Louis and Galena years. A general could not afford even occasional bouts of dissipation. In the army Grant would also lack the firm, restraining hand of his wife. Prolonged absence from Julia could easily set him up for a major relapse into the periodic degradation of his West Coast years. With some notable exceptions, Rawlins largely succeeded in his role as self-appointed watchdog. In later years, Grant’s Galena physician, Dr. Edward Kittoe, paid tribute to “Grant’s repeated efforts to overcome the desire for strong drink while he was in the army, and of his final victory through his own persistency and advice so freely given him by Rawlins.”
The ever-watchful Rawlins enjoyed special license to be frank and even scold Grant. “It was no novel thing to hear the zealous subordinate administer to his superior a stiff verbal castigation because of some act that met the former’s stern disapproval,” said the cipher operator Samuel Beckwith. “And Grant never resented any reprimand bestowed by Rawlins.” Rawlins spoke to him with a freedom that flabbergasted onlookers. Only he could slap Grant on the back or engage in familiar banter. Grant shrank from profanity, yet he tolerated with amusement the barrage of oaths that constantly poured from Rawlins’s mouth.
Because of the purity of his motives, Rawlins became Grant’s closest friend. “Gen. Grant was a man who made friends very slowly,” noted a journalist. “While he had a great many acquaintances, I think he had a very limited circle of friends—I mean men whom he trusted or whose advice he accepted.” Only Rawlins could penetrate the zone of privacy that Grant drew subtly about himself. With his single-minded devotion, Rawlins could confront him with uncomfortable truths and fiercely contest his judgment, spouting opinions in a stentorian voice. With his thoroughgoing skepticism and mistrust of people, he was the ideal foil to Grant’s excessively trusting nature. Rawlins “was always getting excited about something that had been done to Grant,” recalled Lieutenant Frank Parker. When someone showed disrespect for Grant, “he would prance around and say, ‘General, I would not stand such things’ to which Grant would say, ‘Oh, Rawlins! what’s the use in getting excited over a little thing like that; it doesn’t hurt me and it may make the other fellow feel a little good.’”
Perhaps because it contrasted vividly with his listless manner at the Galena store, Rawlins never forgot his initial glimpse of Grant at Cairo: “He had an office in a great bank there, and I was amazed at the quiet, prompt way in which he handled the multitude of letters, requisitions, and papers, sitting behind the cashier’s window-hole, with a waste basket under him, and orderlies to dispatch business as he did.” Fresh from personal calamity, Rawlins threw himself into a whirl of military activity. Before long, he worked day and night, tidying up Grant’s office, creating files, and instituting sound working procedures. Long politically active—Grant thought him the most influential young man in northern Illinois—Rawlins also assisted Grant in perfecting his relations with Washington. When Washburne boasted to Secretary of the Treasury Salmon P. Chase that Grant in Cairo was “doing wonders in bringing order out of chaos,” Rawlins surely deserved much of the credit.
Such was the influence of John Rawlins over Grant that some observers would later exaggerate or misinterpret the nature of his power, attributing to him the military acumen that properly belonged to Grant. He had excellent common sense and swiftly grasped many basic principles of warfare, especially the need to concentrate forces instead of spreading them too thinly. And he became a formidable warrior in his own right, personally signing off on every letter and plan of campaign that came from Grant’s command and never hesitating to differ with him. Nevertheless, Rawlins had no military background and lacked Grant’s general knowledge of warfare. He could never have done what Grant did. While Grant developed tremendous respect for Rawlins’s fearless judgment, it was Grant who originated the plans, Grant who improvised in the heat of battle, and Grant who possessed the more sophisticated strategic sense.