[206] When Stanton suggested Grant be brought east to run the Army of the Potomac, Grant demurred, writing that he knew the geography and resources of the West better and he did not want to upset the chain of command in the East.[209]
Chattanooga (1863) and promotion
Further information: Chattanooga Campaign
Union troops swarm Missionary Ridge and defeat Bragg's army. Published 1886
Lincoln promoted Grant to major general in the regular army (as opposed to the volunteers) and assigned him command of the newly formed Division of the Mississippi on October 16, 1863, comprising the Armies of the Ohio, the Tennessee, and the Cumberland.[210] After the Battle of Chickamauga, the Army of the Cumberland retreated into Chattanooga where they were partially besieged.[211] Grant arrived in Chattanooga on horseback, after a journey by boat from Vicksburg to Cairo, and then by train to Bridgeport, Alabama. Plans to resupply the city and break the partial siege had already been set on foot before his arrival. 