Clue #1: The U.S. flag is, by many, considered to be our national treasure.
Clue #2: Fort McHenry, where the Star Spangled Banner was written, is at Baltimore Harbor - water.
Clue #3: Dark times - I took that as a reference to war.
Clue #4: The tune for the Star Spangled Banner is an old British drinking song.
Clue #5: In the second verse of the anthem, reference is made to mist covering part of the flag the morning after the battle - at first, Key was unsure if the flag flying over the fort was British or American.
The clues tell you what you are looking for, and the puzzle layout tells you where to look. I believe that the circled words are going to ask something to the effect of 'where is the early symbol of American (or, more correctly, U.S.) freedom located (or displayed)?'