George Brinton McClellan was born December 3, 1826 in Philadelphia, Pennsylvania. An excellent student, McClellan graduated from the U.S. Military Academy in 1846 after attending the University of Pennsylvania.

After serving in Mexico under General Winfield Scott, McClellan taught at West Point and observed war in Europe. In 1861, he was named Major General in the Union Army and replaced General McDowell as Commander of the Army of the Potomac after the disaster of Bull Run. McClellan soon became General-in-Chief of the Union Army, but his pompousness and indecision regarding attacks and Confederate retreats resulted in the regrouping of Confederate forces that should have been routed, especially at Seven Points and Antietam. Lincoln lost confidence in McClellan (as did the Union soldiers)and removed him as General-in-Chief. Nevertheless, McClellan was elected governor of New Jersey before his death in 1885