Ulysses S. Grant was actually named Hiram Ulysses Grant at birth. But his dad called him Ulysses because he liked the name. He told a friend who was a senator to write his son a letter of recommendation for admission to West Point. The senator knew his son was named Ulysses, but he didn't know his middle name. West Point required this information, so the senator made it up. He knew that the mother's maiden name was Simpson, and that parents often chose this as a middle name. So he wrote the letter for Ulysses S. Grant. When Grant got to West Point he protested that it was not his real name, but the clerk there (in typical bureaucratic fashion) told him that the letter said it was and therefore it was. Grant had no choice but to agree to it and later he grew fond of seeing his grades posted under "U.S. Grant". So he kept it.