Another website that can be very useful is
http://www.cem.va.gov/ On the left side of the page is a link to National Gravesite Locator. This indexes anyone buried in one of the US National Cemeteries, whether they died in wartime, or later. The names indexed go back to at least the (US) Civil War. When using the search function, I have never gotten a hit when supplying the middle name or initial. The major item missing (in my opinion) is the military service number (probably afraid of listing Social Security Number, but that is irrelevant once someone is dead).
Frank.