George B. McClellan, born in 1826, served as one of the most prominent Union tacticians of the Civil War. McClellan rose to the rank of general and served briefly as the Union Army’s top commander. McClellan’s abilities as a battlefield commander, criticized during his lifetime, have warranted divided appraisals from subsequent historians. Regardless, McClellan had a massive impact on the first years of the conflict, from its buildup to the watershed battles of 1862.

Early Stages of the War

Though McClellan distanced himself from the abolitionist cause, he strongly disagreed with secession and sided with the Union. McClellan’s reputation as a tactician made him a target of heavy recruitment, and he received quick promotion to major general, second only to Lieutenant General Winfield Scott. A sequence of early victories attracted the attention of President Lincoln, who gave McClellan command of the Army of the Potomac. In this role, McClellan excelled as a recruiter of Union forces. McClellan favored a direct march on the Confederate capital of Richmond, which appeared at odds with Scott’s long-term Anaconda Plan. Lincoln eventually adopted a modified Anaconda Plan that left open the possibility for an assault on Richmond.

Commander of Union Forces

In November 1861, George McClellan became head of the Union Army when Winfield Scott retired. McClellan received harsh criticism throughout the four months of his command. Despite the presence of Confederate forces near Washington, McClellan delayed action, and a minor defeat at the Battle of Bull Run affected his reputation. McClellan also had a testy relationship with Abraham Lincoln and disparaged the president in private remarks. Dissatisfaction with McClellan’s dithering led to a Republican-sponsored bill to dismiss him from command. Despite the bill’s failure, Lincoln dismissed McClellan as general-in-chief in March 1862.

Major Campaigns

McClellan retained command of the Army of the Potomac for the Peninsula Campaign to capture Richmond. After the Battle of Seven Pines in Fair Oaks, Virginia ended in stalemate, Robert E. Lee ascended to leadership of the Confederate defense. Lee held his own against McClellan’s forces and succeeded in frustrating the Peninsula Campaign. After this setback, Union forces had a devastating defeat in the Second Battle of Manassas in Virginia. Lee pressed his advantage and initiated the Maryland Campaign into Union territory. Despite having three times the troops of Lee, McClellan delayed a confrontation for reconnaissance. The delay gave Confederate reinforcements time to arrive, and Lee’s army rose from 21,000 to 35,000.

The Disaster at Antietam

McClellan and Lee’s forces met on September 17th, 1862 at the Battle of Antietam near Sharpsburg, Maryland. McClellan’s mismanagement of his own troops resulted in several missed opportunities against the outnumbered and poorly equipped Confederates. The retreating Confederates succeeded in holding off McClellan’s army, and the single-day battle generated 23,000 casualties. Though Lee’s withdrawal made the Battle of Antietam a technical Union victory, McClellan’s failure to crush the Confederates drew harsh criticism. Lincoln stripped the general of command in early November, and McClellan had no further involvement in the Civil War.