“The distinction of firing the first American gun in the war fell to lieutenant Bruce R. Ware of Newton, near Boston, and it occurred on the anniversary of the battle of Lexington, April 19.  Lieutenant Ware had been transferred from the battleship ‘Texas’ to the swift American liner ‘Mongolia’, which had been built for the Pacific trade, but is now plying between the United States and England.   On the last afternoon a periscope was seen dead ahead.

The submarine went under to avoid being run down and rose again two minutes later on one side a thousand yards away.  The stern gun was instantly trained upon her and fired.  The shell shattered the periscope and the submarine disappeared, presumably to rise no more.”

Reference Data:

The Independent, Vol. 90, 1917, page 235