Campaign maps, Army of the Potomac / prepared by command of Maj. Gen. George B. McClellan ; compilation under the direction of Brig. Gen. A.A. Humphreys, by Capt. H.L. Abbot ; engraved by W.H. Dougal ; Julius Bien & Co., photo lith.
MLA
Abbot, Henry L. Campaign Maps, Army of the Potomac / Prepared by Command of Maj. Gen. George B. McClellan ; Compilation under the Direction of Brig. Gen. A.A. Humphreys, by Capt. H.L. Abbot ; Engraved by W.H. Dougal ; Julius Bien & Co., Photo Lith. Corps of Engineers?], 1862. https://collections.library.yale.edu/catalog/15811290.
APA, 6th edition
Abbot, H. L. (1862). Campaign maps, Army of the Potomac / prepared by command of Maj. Gen. George B. McClellan ; compilation under the direction of Brig. Gen. A.A. Humphreys, by Capt. H.L. Abbot ; engraved by W.H. Dougal ; Julius Bien & Co., photo lith. [Maps]. Corps of Engineers?]. https://collections.library.yale.edu/catalog/15811290.