cover General McClellan & Staff, four large portraits (Walcott #289) in black on overall pale green design patriotic cover to Boston, franked with average 3c Rose (65), small faults, 'York Pa. Oct 23' double circle d.s., with original contents headed 'U.S.A. Hospital, York, Penn.', a wounded soldier writing his mother, cover edge faults, otherwise fine, scarcer design