"The bivouac of the dead"

This is the American Monument on the Oa in Islay.  

It was erected in 1920 by the American Red Cross to commemorate  the 700 or more  soldiers and ships crew who lost their lives in two troop ship disasters in 1918 - the Tuscania and the Otranto.   In February  the Tuscania was torpedoed within sight of the headland on which the monument sits whilst in October the Otranto collided with another ship in a storm in Machir Bay, to the north of the site.  

One plaque on the moment has a tribute from President Woodrow Wilson,. Another  contains this verse :

On Fame's eternal camping-ground 
Their silent tents are spread, 
And Glory guards with solemn round 
The bivouac of the dead.

It is from the first verse of a poem by Theodore O'Hara, a Kentuckian who wrote it to honour those who had fallen in the American / Mexican War of 1846.  

The verse appears on many American War Memorials and is even inscribed on the gates at the Arlington National Cemetery.   However because O'Hara fought for the Confederacy during the Civil War and because it was much used  for Confederate graves it was removed from some monuments during the early part of the 20th century and on most is not attributed.