These photographs became two of the most famous of the Civil War, but for over 100 years historians did not question the captions Alexander Gardner wrote for them in his Photographic Sketch Book of the Civil War.

But these are not two different men dead on the battlefield at Gettysburg. They are the same man.

The photographs are on display at the National Archives until July 15 in honor of the 150th anniversary of the battle at Gettysburg.