Timothy H. O'Sullivan, 1863, July, Interior of Breastworks on Round Top, Gettysburg, [Gardner's Photographic Sketch Book of the War. Incidents of the War, pl. 38], Albumen print, Lee Gallery, LL/14029
Timothy H. O'Sullivan, 1865, May, Quarters of Men in Fort Sedgwick, Generally Known as Fort Hell, [Gardner's Photographic Sketch Book of the War. Incidents of the War, pl. 83], Albumen print, Lee Gallery, LL/14038