Ferguson became a soldier [and drummer] during the Civil War, enlisting in Co. A, 21st Mich. Vol. Inf. He was in action only at the battle of Perryville, in which he encountered a degree of hardship which completely exhausted his endurance. On the second night after the engagement he was seated in a chair near the fire, and becoming unconscious from over-fatigue he fell, and was so badly burned as to cause his discharge from the service.