This portrait of McClellan appears in a scrapbook that sets Civil War officers beside a specimen of their handwriting. In this case the portrait is accompanied by a letter from McClellan, written many years after the war while he was Governor of New Jersey, in which he offers his support for what appears to be a widow’s pension request:
The soldier’s name appears to be “Doull,” and there was indeed a single Major Doull serving in the Union Army. Doull seemed to have performed some reconnaissance preserved in this map.
The wife of Major Alexander Doull petitioned for 20 years for a pension as it was believed her husband died due to illnesses associated with his service. In 1880 congress awarded such pension.