Lowell Thomas says: "The most amazing story in American history. It is a Lincoln book that perhaps could not have been written until today–and a book that no man can read without profit. I know of no other short work on Lincoln which presents so much of him and presents it so unforgettably."

Homer Croy says: "It's a wonder! I've always been a Lincoln bug and have read many volumes on him. This comes nearer to making Abraham Lincoln a living, breathing human being than any book that I have ever read. This book takes Lincoln out of the sky, moves him into the house next door and makes a neighbour of him. He's as human as a pair of overalls flapping on the clothes-lines."

Lincoln the Unknown is a biography on Abraham Lincoln, written in 1932 by Dale Carnegie. It is published by Dale Carnegie and Associates, and given out as a prize in the Dale Carnegie Course.

Dale Harbison Carnegie ( spelled Carnagey until c. 1922; November 24, 1888 – November 1, 1955) was an American writer and lecturer and the developer of famous courses in self-improvement, salesmanship, corporate training, public speaking, and interpersonal skills. Born into poverty on a farm in Missouri, he was the author of How to Win Friends and Influence People (1936), a massive bestseller that remains popular today. He also wrote How to Stop Worrying and Start Living (1948), Lincoln the Unknown (1932), and several other books.