137th Pennsylvania Infantry

"At Crampton's Gap, in the South Mountain, [on 14 September 1862] the corps came up with the enemy, and the regiment was here for the first time under fire, though not in the front line. The Pass was carried without its active participation, though the men were eager for the fray, and bore themselves, though almost entirely destitute of knowledge in military duty, with commendable coolness. After crossing the mountain, Colonel Bossert was ordered with a detachment from the different regiments of the brigade, to proceed in the direction of Harper's Ferry, and establish a line across the valley to guard against surprise from that direction. The rest of the regiment was assigned to the charge of the wagon train".

"As the battle of Antietam opened [on 17 September], Colonel Bossert drew in his detachment and re-joined the brigade on the field. The Colonel, with Company I, was sent to the support of the brigade battery, and by his coolness under fire, won the thanks of the commander of the brigade. The main body of the regiment was held in reserve, and after the battle, assisted in burying the dead".

"It was then ordered to stay at Dam No. 4, on the Potomac, where it was engaged in guard duty, and battalion drill."

Tablet #120: Army of the Potomac - 17 Sep, 5 AM to 17 Sep, 12 PM
Tablet #102: Sixth Army Corps - 17 Sep, 5 AM to 17 Sep, 4 PM
Tablet #72: Smith's Division, Sixth Army Corps - 17 Sep, 5 AM to 19 Sep, 9 AM

The quote above from Bates1.