The convention of naming destroyers for men who had served with distinction, usually who had died in service, goes back over a century. When first commissioned the USS John McCain was named for John McCain Sr. and John McCain Jr., the late Senator's grandfather and father. Senior had been the USN's carrier operations guru during WW2, and died shortly after Japan's surrender. Junior had served with distinction in submarines in WW2. Including McCain III in the name of this DDG was done years later.