President Lincoln had taken temporary control of the Union army since General George McClellan, its commander, had fallen gravely ill. Description from civilwardailygazette.com. I searched for this on bing.com/images
November 5, 1862: President Lincoln removes General George B. McClellan from command of the Army of the Potomac. The two men could not stand each other, with McClellan referring to Lincoln as a "great ape", and Lincoln increasingly frustrated with the General's inability to act in the field. Lincoln said of McClellan: "If General McClellan isn't going to use his army, I'd like to borrow it for a time."
Unusual full view image of President Lincoln visiting General McClellan in the general's tent at the Battle of Antietam. Photograph by A. Gardner 1862. Note the captured Confederate flag on the ground. *s*