Editing James A. Garfield (section)

===Chief of staff for Rosecrans===
[[File:GenWmSRosecrans.jpg|thumb|upright|General [[William S. Rosecrans]]]]
Generals' chiefs of staff were usually more junior officers, but Garfield's influence with Rosecrans was greater than usual, with duties extending beyond communication of orders to actual management of his [[Army of the Cumberland]].{{sfn|Peskin|1978|p=176}} Rosecrans had a voracious appetite for conversation, especially when unable to sleep; in Garfield, he found "the first well read person in the Army" and the ideal candidate for discussions that ran deep into the night.{{sfn|Peskin|1978|p=169}} They discussed everything, especially religion, and the two became close despite Garfield's being 12 years his junior. Rosecrans, who had converted from [[Methodism]] to [[Roman Catholicism]], softened Garfield's view of his faith.{{sfn|Peskin|1978|p=170}}

Garfield recommended that Rosecrans replace wing commanders [[Alexander McCook]] and [[Thomas Leonidas Crittenden|Thomas Crittenden]], as he believed they were ineffective, but Rosecrans ignored the suggestion.{{sfn|Peskin|1978|p=177}} With Rosecrans, Garfield devised the [[Tullahoma Campaign]] to pursue and trap Confederate General [[Braxton Bragg]] in [[Tullahoma]]. After initial Union success, Bragg retreated toward [[Chattanooga]], where Rosecrans stalled and requested more troops and supplies.{{sfn|Peskin|1978|pp=180–182}} Garfield argued for an immediate advance, in line with demands from Halleck and Lincoln.{{sfn|Peskin|1978|pp=180–182}} After a council of war and lengthy deliberations, Rosecrans agreed to attack.{{sfn|Peskin|1978|pp=183–189}}

At the ensuing [[Battle of Chickamauga]] on September 19 and 20, 1863, confusion among the wing commanders over Rosecrans's orders created a gap in the lines, resulting in a rout of the right flank. Rosecrans concluded that the battle was lost and fell back on Chattanooga to establish a defensive line.{{sfn|Peskin|1978|pp=205–208}} Garfield, however, thought part of the army had held and, with Rosecrans's approval, headed across [[Missionary Ridge]] to survey the scene. Garfield's hunch was correct.{{sfn|Peskin|1978|pp=205–208}} Consequently, his ride became legendary and Rosecrans's error reignited criticism about the latter's leadership.{{sfn|Peskin|1978|pp=205–208}} While Rosecrans's army had avoided disaster, they were stranded in Chattanooga, surrounded by Bragg's army. Garfield sent a telegram to Secretary of War [[Edwin M. Stanton]] alerting Washington to the need for reinforcements to avoid annihilation. Lincoln and Halleck responded to the request for reinforcements by sending 20,000 troops to Garfield by rail within nine days.{{sfn|Peskin|1978|p=210}} In the meantime, Grant was promoted to command of the western armies and quickly replaced Rosecrans with [[George H. Thomas]].{{sfn|Peskin|1978|p=213}} Garfield was ordered to report to Washington, where he was promoted to major general.{{sfn|Peskin|1978|pp=219–220}} According to historian [[Jean Edward Smith]], Grant and Garfield had a "guarded relationship" since Grant promoted Thomas, rather than Garfield, to command of the Army of the Cumberland after Rosecrans's dismissal.{{sfn|Smith|2001|pp=550–551}}