How did Hiram Ulysses Grant get the nickname Ulysses S. Grant?

Hiram Ulysses Grant was originally named Hiram Ulysses Grant, but when he applied to the U.S. Military Academy at West Point, a senator mistakenly submitted his name as Ulysses S. Grant. Grant decided to keep the name, and it became the one he was known by throughout his military and political career. The "S" in his name does not stand for anything specific; it was simply a part of the name he adopted.