Não é Lincoln.

É o general Thade

Na wikia

...Leo had returned to Earth in his own time only to find technologically-advanced apes in charge and a large statue of Thade in place of Abraham Lincoln on the Lincoln Memorial where it was written:

How Thade achieved his journey to Earth isn't explained, though an insert in the DVD release suggested that he took Leo Davidson's crashed spacepod, went to a point earlier in Earth's history and became a prominent leader in an ape uprising. In contrast, Dark Horse Comics' The Human War suggested that he died in disgrace on Ashlar. His disappearance could possibly have been assumed on his home planet to be a sign of weakness. The ending was intended to form the basis of a movie sequel, plans for which were soon abandoned.