CDV on cardstock mount (toning and light edge wear to print; mount with soiling and wear to edges and corners). Uncredited. Verso bears period ink identification: "William Gamble Col. 8th Ill. Cav. Brig. Gen. U. S. Vols." Gamble is featured sporting thick facial hair and wearing a brigadier general uniform.

Born in Ireland, William Gamble emigrated to the United States in 1838, when he was about 20 years old, enlisting as a private in the 1st US Dragoons, and rising through the ranks to become a sergeant major and fighting in the Seminole Wars. He was discharged in 1843, and worked as a civil engineer in Chicago until the Civil War broke out. He was appointed lieutenant colonel of the 8th Illinois Cavalry on 18 September 1861. The regiment fought in the Peninsula Campaign, when Gamble was wounded in the chest while leading a charge at Malvern Hill. He was promoted to colonel on 5 December 1862, though medical leave kept him away from the important Battles of Chancellorsville and Brandy Station. He returned to the field in mid-June, reaching Gettysburg in time to be one of the first to spot Confederate forces and begin fighting, buying time for the other elements of the Union Army to prepare and position themselves for the battle.

Gamble was brevetted a brigadier general of volunteers in December of 1864, and was eventually given the full rank of brigadier general of volunteers in September of 1865.