1. Grant and Thomas: A Classic Case of Micro-Management - Bad for Business; Worse for Armies.
Grant and Thomas: December, 1864 by Stephen Z. Starr. Courtesy of the Cincinnati Civil War Round Table.
The Starr paper does a masterful job of explaining why Grant mistreated and tried to micro-manage Thomas during the Nashville campaign. However Grant's persecution of Thomas goes farther back than Nashville. Some historians say it started in May of 1862 due to his resentment of having his Army of the Tennessee given to Thomas when Halleck kicked Grant 'upstairs' as his second in command and left him without an active job.
Sometime after he took command of the Western Theatre, I think (opinion alert) Grant made an assessment of his top subordinates to see which ones could challenge him for his job based on ability. First he replaced General William S. Rosecrans with George Thomas to eliminate Rosecrans1. He was worried about Thomas also but had no choice in giving Thomas command of the Army of the Cumberland after his heroic performance at Chickamauga as Stanton and Lincoln would accept no one else. He then proceeded to limit Thomas' opportunities as much as he could. Grant carefully planned the Battle of Chattanooga to spotlight General Sherman so he could be promoted over General Thomas.
In reality, Thomas, a Virginian, had little chance of the top job due to the influence of the Ohio (plus, in the case of Grant, the Illinois) congressional delegations who were quite impressive in forwarding the careers of Grant, Sherman and Sheridan, et al but apparently Grant, who seemed somewhat in awe of Thomas, did not want to chance it.
Grant's promotion of his friend General Sherman, after Sherman had totally failed at Chattanooga, over Thomas was an example of eliminating a rival using army politics of the worst type. Grant rationalized his decision by stating in his memoirs that Sherman was more aggressive. Yet up to that point in the war, Sherman had done very little (if anything) to indicate he had much capacity for independent command while Thomas was a proven winner since January 1862 at Mill Springs. At this point, in any discussion of the abilities of the various Generals, someone will invariably say, 'yes, but Thomas was slow'. This 'logic' is just mindlessly repeating a carefully concocted impression by both Grant and Sherman during the war and especially in their memoirs afterwards to justify, in the case of Grant, not promoting Thomas for merit, and in the case of Sherman, that Grant had made a good choice in picking him over Thomas.2
In reality, punctuality was one of Thomas' quirks. He hated to be late. For example, if he had a part in a coordinated battle plan, he was never late. He did always try to get his ducks in a row before committing his men to the shock of battle, but he always did so as fast as possible. His comprehensive battle planning was really the beginning of the modern Army.3
At Nashville, it was ironic that Grant chastised Thomas for taking so long to bring on battle (two weeks delay due to remount of cavalry and ice storm) while at the same time, Grant had been going nowhere fast against General Lee at Petersburg for six months.
After Thomas' resounding victory at Nashville, Grant rewarded him by taking away his infantry (because he was 'too slow') to make sure he had no more opportunity to outshine Sherman or himself.4
When Grant gave Sherman command of the Western theatre in early 1864, despite the fact that Thomas was senior to Sherman and despite the fact that it was Thomas' men not Sherman's that won the Battle of Chattanooga, General Thomas had good reason to resent the breech of army protocol but, to his everlasting credit, he quietly accepted a command under Sherman during the Atlanta campaign and exerted all his abilities to make the campaign and General Sherman successful. He never let personal issues detract him from his main goal of successfully ending the war.
1. Varney, Frank: General Grant and the Rewriting of History, Savas Beatie, El Dorado, CA, 2013
2. J. H. Sherratt: Some Corrections of Grant's Memoirs as Regards General George H. Thomas; in Commandery of the State of Illinois, MOLLUS, Military Essays and Recollections, vol. II, pg. 499-514, Chicago, IL, 1894.
3. Pratt, Fletcher:Old Pap, Infantry Journal 45 (Jan/Feb 1938): pp. 17-24 & (Mar/Apr 1938): pp. 146-156. Per.
4. Rose, Joseph A. Grant Under Fire, New York: Alderhanna Publishing, 2015, p.517.