Lincoln at Gettysburg Picture Divides Historians: Which One is the President? (PHOTO)

Lincoln's Gettysburg address, the famous speech that extolled the values of a nation of equality after the Civil War, is enough proof that the 16th President was definitely in Gettysburg, Penn. on Nov. 19, 1863. However, a rare photo discovered by amateur historian Christopher Oakley shows that the only real picture of Lincoln could have been someone else entirely- the real Lincoln is a few yards away in the photo, he claims.

Abraham Lincoln at Gettysburg was memorialized in history by his celebrated speech and the dedication of the Soldiers' National Cemetery, but there were only two surviving pictures of the occasion. The second one, found six years ago by amateur historian John Richter, showed the President on horseback while saluting the troops.

However, Oakley, with the help of updated technology, believes Lincoln was a few yards away in front of the speaker's stand. The man on the horse is most likely a member of the Independent Order of Odd Fellows or a military official.

To see a picture of the disputed image, click here.

"For everyone who is seriously interested in that day and in Lincoln at Gettysburg- and there are thousands who are- this merits a very close look," T.A. Frail, a senior editor at Smithsonian magazine, told USA Today. They are publishing a closer look at the annotated photo in their October issue.

Oakley, a former Disney and Dreamworks animator who now teaches at the University of North Carolina-Asheville, stumbled upon the controversy while helping his students with a Virtual Lincoln project. He saw William Seward, the President's Secretary of State, and thought Lincoln would have been closer to him that originally concluded.

After getting a high-resolution image from the Library of Congress- "it's the best $73 I ever spent," he said- he was able to see that Richter's "Lincoln" was most likely a doppelganger. The man straddling the horse had hair that was too long, a fuller beard than the President, and was saluting the troops- a practice no sitting president did until the 1980s, when Ronald Reagan broke protocol.

"All the landmarks (of the man I found)- jawline, beard, hair, cheekbones, heavy brow, ears- line up perfectly," Oakley told Smithsonian magazine. Richter disagrees, saying only the commander-in-chief salutes the troops.

Some historians that once agreed with Richter have now switched sides to Oakley, though.

"The guy on the horse looks like a Cossack. His beard is longer and much fuller than the wispy, trimmed one the president wore in his studio session with Gardner (his photographer) 11 days before," William Frassanito, a historian and author of "Gettysburg: A Journey in Time," explained. "If you're going to spy him in a black speck in a distant background, at least get the beard right."