George Brinton McClellan (December 3, 1826 – October 29, 1885) is a major general during the American Civil War and the Democratic Party candidate for President in 1864.

He organizes the famous Army of the Potomac and serves briefly (November 1861 to March 1862) as the general-in-chief of the Union Army.

Early in the war, McClellan plays an important role in raising a well-trained and organized army for the Union.

Although McClellan is meticulous in his planning and preparations, these characteristics may have hampered his ability to challenge aggressive opponents in a fast-moving battlefield environment.

He chronically overestimates the strength of enemy units and is reluctant to apply principles of mass, frequently leaving large portions of his army unengaged at decisive points.

McClellan's Peninsula Campaign in 1862 ends in failure, with retreats from attacks by General Robert E. Lee's smaller Army of Northern Virginia and an unfulfilled plan to seize the Confederate capital of Richmond.

His performance at the bloody Battle of Antietam blunts Lee's invasion of Maryland, but allows Lee to eke out a precarious tactical draw and avoid destruction, despite being outnumbered.

As a result, McClellan's leadership skills during battles are questioned by President Abraham Lincoln, who eventually removes him from command, first as general-in-chief, then from the Army of the Potomac.

Lincoln offers this famous evaluation of McClellan: "If he can't fight himself, he excels in making others ready to fight."

(McPherson, James M. Tried by War: Abraham Lincoln as Commander in Chief.

New York: Penguin Press, 2008., p. 122) Indeed, McClellan is the most popular of that army's commanders with its soldiers, who feels that he has their morale and well-being as paramount concerns.

General McClellan also fails to maintain the trust of Lincoln, and proves to be frustratingly derisive of, and insubordinate to, his commander-in-chief.

After he is relieved of command, McClellan becomes the unsuccessful Democratic Party nominee opposing Lincoln in the 1864 presidential election.

The effectiveness of his campaign is damaged when he repudiates his party's anti-war platform, which promises to end the war and negotiate with the Confederacy.

He serves as the 24th Governor of New Jersey from 1878 to 1881.

He eventually becomes a writer, defending his actions during the Peninsula Campaign and the Civil War.

The majority of modern authorities assess McClellan as a poor battlefield general.

However, a small faction of historians maintain that he was a highly capable commander, whose reputation suffered unfairly at the hands of pro-Lincoln partisans who needed a scapegoat for the Union's setbacks.

His legacy therefore defies easy categorization.

After the war, Ulysses S. Grant was asked to evaluate McClellan as a general.

He replied, "McClellan is to me one of the mysteries of the war."

(Rafuse, Ethan S. McClellan's War: The Failure of Moderation in the Struggle for the Union.

Bloomington: Indiana University Press, 2005., p. 384)