German U-boat 1918 American Campaign-- Part 3: The Attack On Orleans, Mass.

A few of the U-cruisers also made long voyages south to the Azores and African coast, where they operated generally unmolested against shipping operating in the area.  But one exception was the U-154, which was torpedoed by British submarine HMS E35 off the coast of Portugal in May 1918.

In July 1918, there was an attack by the U-156 on Orleans, Massachusetts, off the coast of Cape Cod in which four barges and a tugboat were sunk.  The U-boat then fired on the town ineffectively for about an hour before it was driven off by two Navy planes.

It was the first attack involving a foreign power's artillery against U.S. soil since the Mexican War.

--Cooter