Born in Philadelphia on December 3, 1826, George B. McClellan graduated from West Point in 1846 before serving in the Mexican War. At the start of the Civil War, McClellan was put in a position of leadership and after a successful campaign in Virginia he was given command of the Army of Potomac, one of the Union's strongest armies. He led the Peninsular campaign with almost 100,000 troops under his command. marching toward Richmond.Although McClellan was a brilliant administrator who possessed good strategic sense, the record shows that he was overcautious and consistently overestimated the strength of his adversaries, always demanding more men and supplies before undertaking offensive action. In 1862, McClellan disagreed with Abraham Lincoln and advanced on Richmond from the east instead of moving directly, against the Confederates at Manassas, Virginia. Although the Union army was successful during the Peninsular campaign, their failure to take Richmond, the Confederate capital, gave the South new motivation. Dissatisfied with the campaign and McClellan, Lincoln replaced him with Henry W. Halleck as commander-in-chief.After the defeat of the Union army. in the Second Battle of Bull Run, . he was again placed in active command of the Army of the Potomac. His overcautiousness at the battle of Antietam on September 17, 1862, led to a draw instead of a Union victory. Because of the heavy Union losses, he was again relieved of his command by Lincoln for the duration of the war.The Democratic Party nominated McClellan in 1864 as its candidate for president a peace platform, but Abraham Lincoln defeated him. After serving as governor of New Jersey From 1878 to 1881, McClellan died in Orange. New Jersey on October 29, 1885.