Alexander Gardner (October 17, 1821 – December 10, 1882) was a Scottish photographer who immigrated to the United States in 1856, where he began to work full-time in that profession.

[2] Gardner was raised in the Church of Scotland and influenced by the work of Robert Owen, Welsh socialist and father of the cooperative movement.

Visiting The Great Exhibition in 1851 in Hyde Park, London, he saw the photography of American Mathew Brady, and thus began his interest in the field.

Finding that many family members and friends at the cooperative he had helped to form were dead or dying of tuberculosis, he stayed in New York.

Gardner was well-positioned in Washington, D.C. to document the pre-war events, and his popularity rose as a portrait photographer, capturing the visages of soldiers leaving for war.

Gardner's relationship with Allan Pinkerton, chief of the intelligence operation that would become the Secret Service, was central to promoting Brady's idea to Lincoln.

Following that short appointment, Gardner became a staff photographer under General George B. McClellan, commander of the Army of the Potomac.

The honorary rank of captain was bestowed upon Gardner, and he photographed the Battle of Antietam in September 1862, developing photos in his travelling darkroom.

], photographic analysis suggested that Gardner had manipulated the setting of at least one of his Civil War photos by moving a soldier's corpse and weapon into more dramatic positions.

[12][13] In 1961, Frederic Ray of the Civil War Times magazine compared several of Gardner's Gettysburg photos showing "two" dead Confederate snipers and realized that the same body had been photographed in two separate locations.

[14] This argument, first put forth by William Frassanito in 1975,[15] goes this way: Gardner and his assistants Timothy O'Sullivan and James Gibson had dragged the sniper's body 40 yards (37 m) into the more photogenic surroundings of the Devil's Den to create a better composition.