Thanks to descendant William B Sheldon for sending along his photograph of Lieutenant Alexander E Sheldon, who commanded Company A of the 4th US Infantry on their foray across the middle bridge over Antietam Creek on 17 September 1862.

Falmouth, Va. Aides de camp to Gen. Joseph Hooker: Capts. William L. Candler, Harry Russell, and Alexander Moore (l to r)

This excellent photograph, taken by Timothy O’Sullivan in April 1863, is in the collection of the Library of Congress.

Captains Candler and Moore, then Lieutenants, were with General Hooker in action at Antietam the previous September.

Russell, late of the 47th New York Infantry (not at Antietam), was appointed Captain and ADC, US Volunteers in October 1862. He resigned shortly after Gettysburg and was again an infantry officer 1864-65.

James J Monaghan was about 25 years old when he was fatally wounded by a gunshot to his head at Antietam on 17 September 1862. His treatment and death are found in the following case study published in the Medical and Surgical History of the War of the Rebellion (1870):

(touch to enlarge)