(1834-1864) Union army officer, one of the ‘Fighting McCooks’, a family of Ohioans who reached prominence as officers in the Union Army during the American Civil War. Two brothers, Daniel and John McCook, and thirteen of their sons were involved in the army, making the family one of the most prolific in American military history. Daniel Jr. was mortally wounded at Kennesaw Mountain, was promoted to Brigadier General for his bravery, and died of his wounds the following day. Excessively rare A.E.S. on a war-time partly-printed document, 1p. 4to., [n.p., ca. Nov. 20, 1862], approving pay to a Uriah Updegraff for services rendered as a regimental wagon maker. McCook pens his endorsement ‘Approved’ and signs boldly in black ink at lower left, adding his contemporary rank ‘Col. 52nd Ohio’. Shows some damp stains away from the signature, toned throughout and with original transmittal folds, otherwise in very good condition overall.