[President Abraham Lincoln, Major General John A. McClernand (right), and E. J. Allen (Allan Pinkerton, left), Chief of the Secret Service of the United States, at Secret Service Department, Headquarters Army of the Potomac, near Antietam, Maryland]

Two weeks after he recorded the carnage at Antietam, Alexander Gardner returned to the battlefield to photograph the visit of President Abraham Lincoln. The president made the seventy-mile journey to Maryland to pay his respects to the wounded on both sides and to confer with his field generals. Gardner made about twenty-five photographs, mostly portraits of a strained meeting between Lincoln and General George B. McClellan, commander of the Union Army of the Potomac. He also made this formal field portrait of Lincoln posed with Allan Pinkerton, his diminutive Secret Service chief (left), and General John McClernand. Founder in 1850 of the eponymous detective agency, Pinkerton proved to be a particularly poor gatherer of military intelligence in his advisory role as a spy for the army. Many believe he significantly overestimated the strength of Robert E. Lee’s forces—an error that dramatically prolonged the war by contributing to McClellan’s extreme caution at attacking the enemy.

Credit: Gilman Collection, Gift of The Howard Gilman Foundation, 2005