The Supplement to the Official Records, part II, vol. 34, serial no. 46, pp. 206-251 indicates that 2nd Lieutenant William H. Harmon died on 21 July 1863, but the place is not given. It is interesting to note the Journal of Dr. Hillary Moseley, who was the Lt. Col. of the 42nd and wounded in the foot at Gettysburg on 1 July. He was taken back to the hospital four miles in the rear and was put in a wagon with Capt. Cooper on 4 July and started back to Richmond, arriving there circa 20 July, give or take 2-3 days. In addition, 2nd Sergeant A. Park of Co. I wrote an account of the battle but did not mention Lt. Harmon by name, yet he does say two of his company's lieutenants were killed and one was wounded on 1 July. The latter would appear to be Lt. Harmon. It is known from the Supplement to the OR that one of the dead officers was 2nd Lt. William L. Waldran who succumbed on 1 July. Given the identical rank, it suggests that either Waldran or Harmon was technically the "Junior" 2nd Lt. of this company. That's all I can add to this mystery.