According to the Lincoln Institute, individuals who knew President Abraham Lincoln personally, including his wife and niece, reported his eyes as grey. Its Abraham Lincoln’s Classroom website references Michael Burlingame’s “The Inner World of Abraham Lincoln,” which includes quotations from Lincoln’s niece.
Burlingame includes in his book a passage written by Lincoln’s niece about an interaction between her aunt and uncle: “When Mary slyly poked fun at him for committing some faux pas, he would look at her quizzically, his grey eyes twinkling, as if to say, ‘How can you attach such great importance to matters so trivial?'”
