The story
From the portrait of Ulysses S. Grant (1822–1885) featured on it. Further etymology The name itself of Grant (who was born Hiram Ulysses Grant) is an alteration by Representative Thomas L. Hamer; Grant’s father wrote to Hamer requesting that he nominate Grant to the United States Military Academy at West Point, New York, which Hamer did in spring 1839. Grant was accepted on July 1. Unfamiliar with Grant, Hamer altered his name, so Grant was enlisted under the name “U. S. Grant”. Since the initials “U. S.” also stood for “Uncle Sam”, he became known among army colleagues as “Sam”. One source states Hamer thought the “S.” stood for Simpson, Grant’s mother’s maiden name, hence some sources list his full name as “Ulysses Simpson Grant”. According to Grant, the “S.” did not stand for anything. Upon graduation from the academy he adopted the name “Ulysses S. Grant”. Another version of the story states that Grant inverted his first and middle names to register at West Point as “Ulysses Hiram Grant” as he thought reporting to the academy with a trunk that carried the initials H. U. G. would subject him to teasing and ridicule. Upon finding that Hamer had nominated him as “Ulysses S. Grant”, Grant decided to keep the name so that he could avoid the “hug” monogram; and it was easier to keep the wrong name than to try changing school records.
Etymology from Wiktionary, CC BY-SA 4.0.