13. President Lincoln on the Field
Lincoln was barely photographed, and most of the images we do have of him are mostly paintings and few studio shots, which is what makes this picture so rare.
This photograph captured President Lincoln, as well as Allan Pinkerton, who went on to head the Secret Service (on the left) and Major General John A. McClernand (on the right), in the battlefield of Antietam, Maryland during the Civil war on October 3rd, 1862.