Thanks - I knew that you, if anyone, would have that info. However, as to the date of Liddell's injury, Longstreet reports that it took place on the evening of the 16th (that is unless it occurred after midnight). From Longstreet's report:

"Crossing the Antietam on the morning of the 15th, Maj. Gen. D. H. Hill's division and my own command were placed in line of battle between the stream and the village of Sharpsburg. Soon after getting into position, we heard of the surrender of Harper's Ferry. This left the portions of the army engaged in the reduction of that garrison free to join us. After much shelling at one point and another of our line, which extended more than a mile on each side of Sharpsburg, the enemy finally attacked General Hood, on my extreme left, late Tuesday evening, September 16. Hood drove him back, but not without severe loss, including that of Colonel Liddell, of the Eleventh Mississippi, an officer of great merit, modesty, and promise."