Lincoln's face is extraordinarily interesting to face-ophiles like myself:
The two sides of his face were asymmetrical which may have been due to disease or to having been kicked in the head by a horse as a young boy.
(Wikipeda also has an entry on his physical and mental health that makes for fascinating reading.)
He aged extremely rapidly while in office (understandable as he had the weight of the American Civil War on his shoulders) but there is speculation that this may have been due to a wasting disease.
He had two life-casts done (NOT death casts) which offer an insight into the real dimensions of his features both before he took office and after.
The face of the Lincoln Memorial sculpture, in Washington DC, must be lit in a certain way to do justice to the dignity of the statue.
It's gratifying that he happened to be President at the dawn of the photography age, so we have photos as well as artistic renderings of our greatest President.
I drew him beardless a few years ago.