James Barbour Terrill was the son of William H and Elizabeth (Pitzer) Terrill and was born February 20th 1838 in Bath County, Virginia. He was an 1858 graduate of the Virginia Military Institute ranking 16th in his class of 19. After graduation Terrill moved to Lexington, Virginia to study law at Washington College with Judge John W Brockenbrough. Virginia Governor Henry A Wise gave him an appointment to the state militia as Major of the cavalry. He began practicing law in Warm Springs, Virginia in 1860.
Terrill was elected Major of the 13th Virginia Infantry in May 1861 when the Civil War started. He served under the then Colonel AP Hill. Terrill's first action at the Battle of First Manassas, in Jackson’s Valley Campaign, and all the other major battles in the Eastern Theater. Following the Battle of Chancellorsville on May 15th 1863 Terrill was promoted to Colonel of the 13th Virginia.
Terrill was killed in action May 30th 1864 at the Battle of Totopotomoy Creek [aka the Battle of Bethesda Church]. Union troops buried Terrill at Bethesda Church, Hanover, Virginia near the battlefield. He had been nominated for promotion to brigadier general, and the appointment was confirmed the next day.