Apparently a favorite of fortune, George B. McClellan was born into a prominent Philadelphia family, graduated second in his West Point class of 1846, successfully served in the Mexican War, and became president of a railroad at the age of thirty-one.
McClellan succeeded to the command of the Union Army of the Potomac after the disaster at Bull Run (Manassas) in July 1861. A brilliant organizer, he inspired devotion in his troops and transformed the army. In the field, though, he lacked dash and aggressiveness.
His caution was legendary. "If McClellan is not using the army," President Lincoln once said, "I should like to borrow it for a while." He advanced so slowly toward Richmond in the spring of 1862 that his critics dubbed him the " Virginia Creeper." At Antietam, he missed several opportunities to crush the Confederate army. Yet, Antietam did give McClellan a well known name when President Lincoln used the battle for a reason to give his Emancipation Proclamation.
Lincoln relieved McClellan after Antietam and he never saw field again. In 1864 he was once again defeated by Lincoln, this time for Presidency.