Barbour also served among Virginia's delegates to the 1860 Democratic National Convention, and as a major in the Confederate States Army during the American Civil War.

He was among the sons of John S. Barbour, Member of the U.S. House of Representatives from Virginia's 15th congressional district, and his wife Ella A.

During the American Civil War, Culpeper County voters again elected James Barbour to the Virginia House of Delegates; he served during the sessions 1861/62, 1862 (April), 1862 (September), and 1863 (January).

[2] About six months later, the Battle of Brandy Station, perhaps the largest cavalry engagement of the conflict, took place on and around the Barbour family's estate.

After the war, Barbour acquired a controlling interest in the Richmond Daily Enquirer and Examiner on July 15, 1867, and became its editor.

[12] In 1877, Barbour returned to the Virginia House of Delegates, succeeding his relative Thomas B. Nalle for one term, after which fellow Confederate veterans Jonathan C. Gibson or Jacob S. Eggborn held the seat.