John Clifford Pemberton was a career U.S. Army officer and veteran of the Mexican, Seminole and Mormon wars who, though born and raised in Pennsylvania and with two brothers serving in the Union army, entered into Confederate service a brigadier general in 1861. He advanced to the rank of major general when he became the commander of the Department of South Carolina, Georgia and Florida. In October 1862, he was promoted to lieutenant general and assigned to oversee the Department of Mississippi, Tennessee, and East Louisiana.
In 1863, after a prolonged siege at Vicksburg, Mississippi, Pemberton was forced to surrender his command and the city to Ulysses S. Grant. Following his exchange, he was unable to secure another assignment. Finally in May 1864, he resigned his commission as lieutenant general to accept an appointment as a lieutenant colonel of artillery, under which he commanded the artillery in the defenses of Richmond and served as inspector general of the artillery until the end of the war.
After the war, he lived a quiet life on his farm in Warrenton before moving the Phildelphia in 1876, where he died five years later.