The Battle of South Mountain commenced at about three in the afternoon, and lasted till half-past nine at night. The wounded were removed promptly, as they fell, to houses in the vicinity and to Middletown, and all were removed before daylight the following morning. Nothing was lacking for the wounded. After the churches at Middletown became crowded with wounded, the surplus were sent to Frederick in ambulances ...
On our arrival at Keedysville, another battle was evidently imminent. By order of the medical director, I examined and selected the buildings in town best adapted for hospitals, supervised the necessary preparations, and placed surgeons in charge of the respective hospitals. Surgeon James L. Farley, 84th New York Volunteers, was instructed to act as surgeon in chief of all the hospitals. Two hundred additional ambulances, which I had conducted from Middletown during the night, were in readiness near general headquarters. Hospital tents were entirely wanting. There were on hand no reserve supplies of medicine and hospital stores. Each command had to rely on what they brought with them in their forced marches. Some raw regiments had been hurried forward without medical supplies, and the remainder had, as a rule, an unusually small amount on hand. On September 17th, I was the only remaining medical officer on duty with the director, Surgeon Letterman, the rest of his assistants having been detached to Middletown, Crampton's Gap, and elsewhere, and, according to his instructions, I visited the centre and right of our position, and made the best arrangements I could for the distribution of the wounded. I found several commodious farm-houses, a large barn, and good water at convenient distances, and a large flour mill also, and directed that they should be occupied ...
The wounded were numerous, and it was necessary to lay many of them in the yards contiguous to the houses, that they might be supplied with food from their kitchens, and have their wounds dressed in the open air ...
A few days after the battle, many of the wounded were collected and sent to Frederick in ambulances. Trains continued to transport them until all who could be safely removed were disposed of. The remainder were subsequently collected at Smoketown in a single hospital, as soon as the hospital tents arrived. This hospital under canvas was the most perfect field hospital which I had seen up to that period. It was under the charge of Surgeon B. A. Vanderkieft, U. S. V. Medical supplies, limited in quantity, were received from Frederick, and a medical purveying depot was established at Sharpsburg under my superintendence ...
From the 18th to the 30th of September, the days were very warm; but there usually came a dense and cold fog, which lasted till about nine o'clock the next morning, the fog had a very disagreeable odor, as if impregnated with exhalations from dead bodies on the battlefield. As after most engagements, many of the wounded were destitute of blankets, and it was impracticable to provide them with shelter. This may serve to explain the prevalence of diarrhoea which was greatest about September 24th. Unfortunately, the purveyor was unable to supply the astringents required. I suspected that this diarrhoea had a specific intermittent character, and recommended the use of quinia, combined with Dover's powder, as a substitute for astringents, and this medication had great success. The wounded Confederate prisoners, who were in hospital near Sharpsburg, were generally in an asthenic condition. Tetanus was observed almost exclusively among them, and was seen chiefly amongst those who had marched, before the battle, not less than thirty miles in twenty-four hours. The exposure to which they were subjected during the hot days and cold nights, in which the enemy were effecting their retreat, appeared to have strongly predisposed them to this disease ...
The Fifth Corps crossed into Virginia at Harper's Ferry, and, on November 2d, its second division occupied Snicker's Gap, and was positioned so as to protect the road. On the following day, this division advanced four miles beyond the Gap, and a brisk skirmish ensued, in which about thirty were wounded. They were carried on stretchers to the vicinity of the camp, and all necessary operations were performed the same night. Next morning they were carried to a church two miles in the rear, and on November 7th, they were taken in ambulances to White Plains, and thence by railroad to Washington ...
Source: Second Extract from Memoranda for the Surgical History of the War1
1 Barnes, Joseph K., and US Army, Office of the Surgeon General, The Medical and Surgical History of the War of the Rebellion, 6 books, Washington DC: US Government Printing Office, 1870-1883, Part. 1, Vol. 1, Appendix, pp. 104-105 [AotW citation 19729]