I ask the acceptance of this resignation. Capt. Lusk has been in most of the battles including the First Bull Run, from Beaufort to the death of Major-Gen. Stevens, whose Staff he was on from the date of Gen. Stevens's promotion to his death. Capt. Lusk, so soon as he heard of the occupation of Maryland Heights, left New-York City, came to Point of Rocks, and walked to Harper's Ferry, and volunteered for duty at a moment when I was much in need of his services, and to make him available I recommended him for the appointment of Asst. Adjt.Genl. and he was appointed accordingly, with the expectation that when the prospect of fighting at that point was over, his resignation would be accepted. Under the circumstances, as Capt. Lusk is on the point of commencing a professional life in the City of New-York, I ask the acceptance of his resignation, knowing that there never will be an emergency like that at Gettysburg and Maryland Heights, that Capt. Lusk will not be found at the front.
SOURCE: William Chittenden Lusk, Editor, War Letters of William Thompson Lusk, p. 294