Ciphers sent commencing April 29th 1863

75 pages; 36 x 28 cm. Title from note on first page. No spine or cover labels. Fully in code; appears to be solely for the Headquarters, Army of the Potomac, not Fort Monroe. Approximately 231 telegrams, 7 of which have been partially or completely crossed out. P. 76-199 and 280-400 are blank. Telegrams begin on front fly leaf 2.