McClellan George Brinton (1826–1885), a United States army officer. As commander of the Union Army of the Potomac, 1861–62, McClellan directed troops in the eastern theater of Civil War operations. He was an outstanding organizer and capable strategist, but was overcautious as a field commander, always demanding more men and supplies before undertaking offensive action. President Lincoln often complained of his slowness to attack the enemy, and finally removed him from command.

McClellan was born in Philadelphia. He left the University of Pennsylvania to enroll at West Point. After graduation in 1846 he served in the Mexican War, and received the brevet rank of captain for bravery at the Battle of Chapultepec (1847). McClellan taught military engineering at West Point, 1848–51, and later served as an army engineer in the West and as a military observer in Europe. In 1855 he designed the McClellan saddle, which long remained the standard cavalry saddle. McClellan resigned from the army in 1857 and became a railway executive.

Civil War Commander

Soon after the outbreak of the Civil War, McClellan was made a major general and given command of the Department of the Ohio. His occupation of the pro-Union northwestern section of Virginia in the summer of 1861 opened the way for its organization as the state of West Virginia. Taking charge of the Army of the Potomac in July, 1861, he drilled it into a spirited fighting force.

In March, 1862, McClellan began the Peninsular Campaign. He intended to capture Richmond by way of the peninsula between the York and James rivers. McClellan's troops won the Battle of Fair Oaks and successfully repulsed Confederate attacks during the Seven Days' Battles, but failed to take the Confederate capital. Throughout the campaign McClellan overestimated the strength of the Confederate army.

At the Battle of Antietam (September 17, 1862) McClellan halted a Confederate invasion under General Robert E. Lee. However, he did not pursue the retreating enemy and, as a result, was relieved of his command in November and replaced by General Ambrose E. Burnside. McClellan went to his home in Trenton, New Jersey, and never again saw field service.

Politician and Engineer

In the 1864 Presidential election McClellan was the Democratic candidate opposing President Lincoln. The Democratic platform called for peace first and negotiations to restore the Union afterwards. McClellan, however, ignored the platform, believing the war would have to be won before the Union could be reestablished (a position similar to Lincoln's). He was soundly defeated by Lincoln, receiving 21 electoral votes to Lincoln's 212. The popular vote was 2,206,938 for Lincoln and 1,803,787 for McClellan. McClellan resigned from the army on election day.

After spending three years in Europe, McClellan supervised the construction of a new type of steam warship, which was never completed for lack of funds. He was chief engineer of the New York City docks, 1870–72, and governor of New Jersey, 1878–81. McClellan's Own Story (1887) is his memoirs.

George Brinton McClellan (1865–1940), his son, was a Democratic member of the U.S. House of Representatives, 1895–1903, and mayor of New York City, 1903–09. He was professor of economic history at Princeton University, 1912–31.