RMS Lusitania

The RMS "Lusitania" was a British Ocean Liner. Built in 1907, the ship is best known for being sunk by Germany. 
Many believe the Lusitania was carrying ammunition to British troops when it was torpedoed by a German U-Boat (U-20) early on 7 May 1915 during World War I. 
More than a thousand people were on board, including 128 Americans. They were killed when the ship sank. At first President Woodrow Wilson only asked the German government to apologize and compensate the families of the victims. 
Two years later, this and other events led to the United States joining World War I on the Allied side.