The earliest known photograph of a president of the United States is a faint and scratched daguerreotype likeness of John Quincy Adams, who served as chief executive from 1825 to 1829 and later as a member of Congress until his death in office in 1848. This likeness of the former President Adams was taken at the gallery of Bishop and Gray in early August 1843 in Utica, New York. President Adams, then 76 years old, was returning from a visit to Niagara Falls and stopped at Utica to see an old friend, Judge Ezeikiel Bacon. In his diary for August 1, 1843, Adams remarked, “Four daguerreotype likenesses of my head were taken, two of them jointly with the head of Mr. Bacon. All hideous.” Adams continued his diary entry the following day, “At seven this morning Mr. Bacon came and I went with him to the Shadow Shop, where three more Daguerreotype likeness were taken of me, no better than those of yesterday. They are all too true to the original.”
The photograph of Lincoln also involves a modern day find (giving us art historians hope!). Bruce and I went to Gettysburg last summer and it was an incredible place and experience. It truly blew me away. Here is the account from the Library of Congress and the picture (he is in the center of the detail, with the bow tie looking down) now housed at the National Archives:
The plate lay unidentified in the [National] Archives for some fifty-five years until in 1952, Josephine Cobb, Chief of the Still Pictures Branch, recognized Lincoln in the center of the detail, head bared and probably seated. To the immediate left (Lincoln's right) is Lincoln's bodyguard, Ward Hill Lamon, and to the far right (beyond the limits of the detail) is Governor Andrew G. Curtin of Pennsylvania. Cobb estimated that the photograph was taken about noontime, just after Lincoln arrived at the site and before Edward Everett's arrival, and some three hours before Lincoln gave his now famous address.
Both images are copy prints from the National Archives (http://www.loc.gov/exhibits/gadd/gaphot.html) and (http://www.loc.gov/exhibits/gadd/images/platform.jpg)