Final answer:
General McClellan delayed his capture of Richmond due to strong Confederate defenses, poor weather, challenging terrain, and diversion of troops to protect Washington, D.C. His cautious approach aimed at preserving his forces but resulted in missed opportunities, leading to significant casualties during the Seven Days Battles and ultimate retreat without capturing Richmond.
Step-by-step explanation:
General McClellan delayed pressing forward to capture Richmond during the peninsular campaign in May of 1862 for several reasons. After landing his army at Fort Monroe, Virginia, his advance was slowed by encountering Confederate defenses. Soon after, the weather took a turn for the worse, and following engagements with the Confederates, General McClellan's progress was further hindered. Moreover, the Confederate commander, General Joseph Johnston, was wounded and replaced by General Lee, who took the time to reorganize and strengthen Richmond's defenses.
During the advance, McClellan faced difficult terrain including heavy forests and swamps along the Williamsburg Road. Despite his goal of placing artillery batteries close enough to threaten the city, his offensive gained little ground and suffered over 1,000 casualties.
Additionally, a portion of McClellan's forces was drawn away to defend the nation's capital against a potential threat from Confederate General Thomas "Stonewall" Jackson's forces. The consequent shifting of troops left the army near Richmond more vulnerable. This, combined with hesitant strategies that aimed at conserving troops rather than seizing decisive victories, culminated in the Seven Days Battles, which caused substantial Union and Confederate casualties without any conclusive outcome for McClellan's campaign.