What did the ''s'' in Ulysses S GRANT'S Name?

Answer:
President Grant was born Hiram Ulysses Grant. Congressman Thomas Hamer mistakenly nominated him to the U. S. Military Academy as "Ulysses S. Grant of Ohio." At West Point, he adopted this name with a middle initial only. His nickname became "Sam" among army colleagues at the academy, since the initials "U.S." stood for "Uncle Sam".
First answer by Armoryhistorian. Last edit by Lawdog1881. Contributor trust: 119 [recommend contributor recommended]. Question popularity: 4 [recommend question].