In 1861, when the American Civil War started, Miller was owned by Anne's son, Robert McBride. In September 1861, Robert's brother, Captain John J. McBride of Company E of the Fifth Texas Infantry Regiment in the Confederate Army, secured Miller as a personal servant. When Captain McBride was wounded in the Second Battle of Bull Run in late August 1862, Miller attended him in the hospital until his recovery. McBride recovered and Miller attended him at the Battle of Fredericksburg in December 1862 and in the Suffolk Campaign the next spring.