The ever so cautious Major General George B. McClellan was confident that he was facing a Confederate army during the Peninsula campaign that was actually smaller than he believed it really was. To prevent a major reversal in his advance towards Richmond, McClellan ordered that entrenchments and field fortifications were built at the end of each day's march. This was a sound practice, however, his overestimates of the size of the enemy's armies and the time to build field fortifications slowed his advance.
The battles referred to as the Seven Days were fought during Union General George McClellans Peninsula Campaign, and began June 25, 1862 and ended July 1. There would be six separate battles.
George McLellan
During the Peninsula campaign the fighting for Richmond began at Fair Oaks. General Johnston was wounded during his attack on Union forces and was replaced by General 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.
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.
5 miles
The failed Peninsula Campaign in July 1862 was frustrating for Lincoln. One result of this was Lincoln's appointment of General Halleck as general in chief. Halleck was thus appointed at this time to handle General George B. McClellan's problems.
President Lincoln took the advice of generals Hitchcock and Thomas on the number of troops that were needed to protect Washington DC as the Peninsula campaign was about to begin. As a result, General McDowell's corps were removed from General McClellan's army as the Peninsula campaign was almost ready to begin.
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.
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.
A more cautious Confederate general was replaced by the more aggressive Robert E. Lee.
In the midst of the McClellan Peninsula campaign, Confederate General Joseph Johnston was wounded and was out of action. Jefferson Davis was aware of Robert E. Lee's talents, and had placed Lee in charge of defeating the Peninsula campaign. Lee was always a well respected Union commander. With his success in the Peninsula campaign, Lee took over Eastern Confederate military operations.