Title: Diogenes his lantern needs no more, an honest man is found! the search is o'er Source: Library of Congress Prints & Photos Catalog

The roots of this nickname start in his early working life. As a young man, Abraham Lincoln worked as a general store clerk. One evening he was counting the money in the drawers after closing and found that he was a few cents over what should have been in the drawer. When he realized that he had accidentally short-changed a customer earlier that day, Lincoln walked a long distance to return the money to the customer. On another occasion Lincoln discovered that he had given a woman too little tea for her money. He put what he owed her in a package and personally delivered it to the woman--who never realized that she was not given the proper amount of tea until Lincoln showed up at her doorstep!

Lincoln’s integrity and insistence on honesty became even more apparent in his law practice. In his book, An Honest Calling: The Law Practice of Abraham Lincoln, Mark Steiner notes that:

A relative by marriage, Augustus H. Chapman, recalled: “In his law practice on the Wabash Circuit he was noted for unswerving honesty. People learned to love him ardently, devotedly, and juries listened intently, earnestly, receptively to the sad-faced, earnest man…I remember one case of his decided honest trait of character. It was a case in which he was for the defendant. Satisfied of his client’s innocence, it depended mainly on one witness. That witness told on the stand under oath what Abe knew to be a lie, and no one else knew. When he arose to plead the case, he said: “Gentlemen, I depended on this witness to clear my client. He has lied. I ask that no attention be paid to his testimony. Let his words be stricken out, if my case fails. I do not wish to win in this way.”

Lincoln carried his regard for the truth through his years at the White House. He, himself, was forthright and deeply sincere. It seems as if some of his colleagues wondered if he could ever tell a lie. During the Civil War, President Lincoln stated, "I hain't been caught Lying yet, and I don't mean to be." [Rufus Rockwell Wilson, Lincoln Among His Friends: A Sheaf of Intimate Memories (Philip Clark, "A Friend of Lincoln's New Salem Days"), p. 65.] For Lincoln, the truth was not worth sacrificing for any gain, no matter how large that gain may have been.

Lincoln didn't need to lie to save the Union, to unite the people, and free slaves, and lead a nation. Perhaps that is why he remains a hero to so many around the world, and an inspiration to leaders well into the future. From his work as a clerk to his duties as a president, Lincoln’s honesty was unwavering, showing that telling the truth is an essential lesson for all, no matter who you are or what you do.

Sources:

"Abraham Lincoln's Personality" By Richard Behn.
Featured on Abraham Lincoln's Classroom.

"Abraham Lincoln and The Eighth Circuit" By Mark E. Steiner.
Featured on Abraham Lincoln's Classroom.