[202][203]

General McClellan
After the Union rout at Bull Run and Winfield Scott's retirement, Lincoln appointed Major General George B. McClellan general-in-chief.[204] McClellan then took months to plan his Virginia Peninsula Campaign. McClellan's slow progress frustrated Lincoln, as did his position that no troops were needed to defend Washington. McClellan, in turn, blamed the failure of the campaign on Lincoln's reservation of troops for the capital.[205]

Lincoln and McClellan, October 3, 1862
In 1862, Lincoln removed McClellan for the general's continued inaction. He elevated Henry Halleck in July and appointed John Pope as head of the new Army of Virginia.[206] Pope satisfied Lincoln's desire to advance on Richmond from the north, thus protecting Washington from counterattack.[207] But Pope was then soundly defeated at the Second Battle of Bull Run in the summer of 1862, forcing the Army of the Potomac back to defend Washington.[208]
Despite his dissatisfaction with McClellan's failure to reinforce Pope, Lincoln restored him to command of all forces around Washington.[209] Two days after McClellan's return to command, General Robert E. Lee's forces crossed the Potomac River into Maryland, leading to the Battle of Antietam.