McClellan's Peninsular campaign failed because the Confederate army was defending Richmond better that McClellan anticipated. They retreated, then turned and attacked McClellan, surprising the Union general.
George McClellan
George McClellan
It was known as the Peninsular Campaign.
The basic weaknesses of George McClellan were displayed during the Peninsular Campaign. McClellan was paranoid, convinced that the enemy was stronger than he was, and became overly cautious. He was slow to attack, even when he possessed overwhelming military strength, and retreated quickly when attacked by the enemy, even when his army outnumbered the Confederates and inflicted heavy casualties on them.
President Lincoln appointed Major General George B. McClellan to general in chief on November 1, 1861. He replaced the retiring General in Chief Winfield Scott. Lincoln relieved McClellan of his title on March 11, 1862. McClellan was not in Washington DC at this time. He was in the process of organizing the Peninsula campaign. It is written that Lincoln did not believe that McClellan could hold his position as general in chief and conduct the Peninsula campaign at the same time.
Union General George B. McClellan had plans for General Totten in the 1862 Peninsula campaign. Late in March of 1862, McClellan had requested that General Totten be made available to build fortifications on the peninsula leading to Richmond. He was an experienced engineer. McClellan understood that the experience of the Army's chief engineer, Totten would be invaluable in this campaign.
The Seven Days Battles was the number of battles in the Peninsula campaign under George B McClellan.
As the Union's Peninsula campaign was in its early stages, General McClellan was certain that President Lincoln was hampering McClellan's war operations. Lincoln had stepped in and retained the corps under General McDowell to defend Washington DC. Lincoln believed this was a necessity.
General George B. McClellan's telegraph to Secretary of War Edwin Stanton on June 28, 1862 bordered on treason. When McClellan's telegraph was received by General Dix in Washington DC, Dix omitted McClellan's claim that the Lincoln administration purposely acted to create the Peninsula campaign as a failure.
Union General George Meade still believed that a "peninsula campaign" was the best way to assault Richmond. Meade did not press his ideas because of the 1862 failed Peninsula campaign of General George B. McClellan.
A more cautious Confederate general was replaced by the more aggressive Robert E. Lee.
General McClellan believed he had good reasons for his ideas that Washington DC was set about to damage his plans for the Peninsula campaign. He resented his battle plans being questioned, having his army reorganized against his will, and to read in newspapers about his removal from the general in chief title he had. From that point on, he began his campaign of blaming Washington DC for his failures in the Peninsula campaign.