George Brinton McClellan is often remembered as the great organizer of the Union Army of the Potomac. Nicknamed "Young Napoleon," "Little Mac" was immensely popular with the men who served under his command. His military command style, however, put him at odds with President Abraham Lincoln, and would ultimately upset his military and political fortunes.
McClellan began his military career after entering the United States Military Academy in 1842. He graduated second in a class of 59 in 1846, along with 20 others who would become full rank generals during the Civil War. He was appointed as a brevet second lieutenant in the Corps of Engineers and served under General Winfield Scott during the Mexican-American War, helping to construct roads and bridges for the army. The recipient of brevet promotions to both first lieutenant and captain, he returned to West Point as an instructor after the war, and helped translate a French manual on bayonet tactics. Other duties included service as an engineer at Fort Delaware, expeditions to explore the Red River, and the exploration possible routes for the transcontinental railroad. He was also a military observer during the Crimean War. In 1857, McClellan resigned from the military to take a position with the Illinois Central Railroad.
Upon the outbreak of the Civil War, Ohio governor William Dennison appointed McClellan major general of Ohio Volunteers on April 23, 1861. This promotion, along with the support of Governor Denison, encouraged Lincoln to commission McClellan a major general in the Regular Army, making him one of the highest ranked individuals in the service under only Winfield Scott. McClellan began his work swiftly, ensuring that Kentucky would not secede from the Union. He then commanded forces during the Rich Mountain campaign in what is now West Virginia to ensure that the portion of the state would not be fully taken by Confederates. This success, combined with the defeat of General Irvin McDowell at the battle of First Bull Run, led McClellan to become commander of the Army of the Potomac, and later General-in-Chief of all Federal armies upon the retirement of General Winfield Scott’s in November 1861.
It was during this time that McClellan cemented his bond with the men of the Union army. Although many politicians and generals harbored resentment toward McClellan, he was largely revered by his men. After the defeat at Manassas, much of the Army of the Potomac was unorganized, and its new commander set to work providing the men proper military training and instilling in them a remarkable esprit de corps. As he built his army, however, McClellan also became wary of Confederate forces, fearing that he faced numbers many times his own.
In the spring of 1862, McClellan was removed as General-in-Chief, though he retained command of the Potomac Army. Facing great pressure from Lincoln, he launched a campaign against the Confederate capital along the Virginia Peninsula, known as the Peninsula Campaign. Continually tricked by Confederate commander General Joseph E. Johnston that he was facing a large force, McClellan frequently delayed his attacks, allowing his opponent ample time to retreat slowly toward the Richmond defenses. A surprise attack by Rebels at the battle of Seven Pines (or Fair Oaks) blunted the already sluggish Federal advance. Although the Union army repulsed the attacks, McClellan to again delayed any further movement, hoping for more reinforcements to come from Washington. Seven Pines had another adverse impact on the campaign. During the battle, Confederate General Johnston was wounded, and Robert E. Lee was appointed to replace him. Taking advantage of McClellan's cautious streak, Lee hammered at the inert Army of the Potomac in a series of fierce and unrelenting assaults. Over the course of the bloody Seven Days' Battles, McClellan’s mighty host was forced to abandon its bid to seize Richmond and retreat to the safety of Washington. As a result of the failed campaign, Lincoln named Henry Halleck as General-in-Chief of the army, and the Army of the Potomac was given to General John Pope.
Following Pope's failure to capture Richmond the subsequent Union defeat at the battle of Second Manassas, McClellan was once again leading the army that had such strong affection for him. With Little Mac at its head, the Army of the Potomac moved to counter Lee's 1862 invasion of Maryland. The Union chief molded his campaign around a captured a document outlining Lee’s invasion plan. After a series of skirmishes along the Blue Ridge mountains, the two armies met in an epic contest at Antietam on September 17, 1862, the single bloodiest day of the war. Battle weary and bloodied, the Confederate Army retreated back into Virginia under the cover of darkness.
Though he had managed to thwart the Lee's plan to invade the North, McClellan's trademark caution once again denied the Northern cause a decisive victory, and the once-cordial relationship between the army commander and his Commander-in-Chief had been badly damaged by the former's lack of success and excessive trepidation. After the battle, a disappointed Lincoln visited McClellan in camp to express his frustration at the general's inability to capitalize on this most recent success. The general countered by saying the army needed time to rest and refit. In November of that year McClellan was relieved of command for the last time and ordered back to Trenton, New Jersey to await further orders, though none ever came.
In 1864, McClellan became involved in politics when he was nominated to be the Democratic candidate for president against his former boss, Abraham Lincoln. McClellan ran on an anti-war platform, promising that he would negotiate peace terms with the Confederacy to help end the war as soon as possible. But by November of 1864, a string of Union successes had convinced many that the war was in its final phase. McClellan resigned his army commission on Election Day, but ultimately Lincoln was elected to a second term.
After the war, McClellan served as an administrator for a number of engineering firms and in 1878 was elected Governor of New Jersey. In his final years, the former general penned a defense of his tenure as commander of the Army of the Potomac, but died before he could see it published. George McClellan is buried in Trenton, NJ.
The Civil War Trust had the opportunity to speak with Mr. Richard Slotkin on his new book, The Long Road to Antietam. This interview covers not only the military aspects of the 1862 Antietam Campaign, but also the important political factors affecting both the Confederate and Federal governments.