William A. Crafts, Life of Ulysses S. Grant: His Boyhood, Campaigns, and Services, Military and Civil.

[8] Hamer gave his name as Ulysses S. Grant, probably confounding his name with that of a brother who bore the name of Simpson, his mother's maiden name. Grant applied to the authorities at West Point, and subsequently to the secretary of war, to have the error corrected, but those parties apparently did not think the matter of sufficient importance to demand their attention; or possibly they thought that the initials U. S. were very appropriate for a cadet educated at the expense of the United States, and destined to be an officer in the army of the United States. At any rate, the request was not complied with, and it was fated that Hiram Ulysses Grant was henceforth to be known as Ulysses S. Grant.

These initials were highly popular with the cadets, who soon gave Grant the nickname of “Uncle Sam,” which he always retained in the army among the associates of his youth. They have proved popular with the people, too, who have delighted to associate with his the abbreviation of the national name, which he did so much to preserve. His first great victory, when he dictated terms to the rebels, gave other popular names to his initials, and he was enthusiastically hailed as “unconditional surrender” Grant. The name which a blunder assigned to him has thus become so identified with the history of the country, and with the love and admiration of the people, that neither he nor they could change it, or would desire to if they could.

At West Point, as at school, young Grant was not a brilliant scholar; but he was diligent in his studies, and by his persistency overcame all difficulties, and thoroughly