To answer your questions one by one:
Herbert Walker is considered one middle name. I now however realize that the 43rd president's middle name isn't here. I will change that now.
As for Grant, while president his name was "Ulysses S. Grant." Ulysses was his original middle name, but not while he was president ("Dwight" and "Lynch" are bonuses for similar reasons).
And the S. actually didn't stand for anything, like Truman's--I did once think it was Simpson, but that turns out not to be the case. http://www.granthomepage.com/grantfacts.htm |
U.S. Presidents 
Famous Wars 
Original 13 Colonies
