He was a son of Stephen West Moore, a prominent banker in Charleston (originally from Virginia), and his wife, Eleanore Screvan Gilbert.

Moore was educated in the local public schools of Charleston, and then attended South Carolina Medical College with the intention of becoming a physician.

[2] In this capacity he serviced in the American frontier, including regions of Missouri, Kansas, Florida, as well as along the Texas border with Mexico.

[4] Following the war with Mexico, Moore served in several U.S. Army postings, including a short stint at the United States Military Academy at West Point as a surgeon.

[1] After the state of Arkansas seceded from the Union, Moore was approached by Jefferson Davis to join the Confederate cause, who cited "the army’s unfortunate military situation and the lack of trained medical men..." to persuade him[4] On March 16 Moore was assigned to lead the new Confederate Army Medical Department as surgeon general.

He improved the field ambulance corps and supplemented the few available medicines with drugs made from the South's indigenous plants, which were produced in laboratories set up by Moore.

[4] In 1864 Moore established the Confederate States Medical and Surgical Journal, a manual to instruct the surgeons throughout the army; it included both exact descriptions and drawings of operations.

[4] During the war Moore also founded the Association of Army and Navy Surgeons of the Confederate States of America.

However, Military historian Bruce Allardice considers Moore to be a brigadier general, as did Confederate Veteran magazine.