By September 18, Davis had recuperated to the point that he could resume command of the forces defending against the Confederate threat to Louisville. On September 20, Davis reported to Nelson. Nelson was quite an imposing figure over Davis. Nelson got his nickname, "Bull," in no small part to his stature. Nelson was 300 pounds and six feet two inches and was described as being "in the prime of life, in perfect health." Davis was quite small in comparison, measuring five feet nine inches and reportedly only 125 pounds. Nelson ordered Davis to take charge of organizing and arming the citizens of Louisville to prepare for its defense.