Since World War One had started, travelling across the oceans had become very dangerous for the Allies as the German submarines sunk many of their ships in what was known as a ‘naval blockade’ of Britain and her allies.
This was an attempt to prevent ships getting in and out of Britain with supplies and troops that would have helped with the war effort and the British had a similar blockade of Germany for the same reasons.
On the 1st May 1915, the ocean liner RMS Lusitania set sail from New York carrying 1,959 passengers, who were mainly British with 128 Americans.
The German embassy found out about this and issued a warning which basically said that they couldn’t guarantee their safety and that they shouldn’t sail on the ship because it might be sunk by U-boats (submarines).
Six days later, on the 7th May, the ship was torpedoed by a German U-boat and sunk very quickly. Of the 1,959 passengers, 1,198 died, including all of the Americans.
The effect of the sinking was tremendous and sent shock waves all around the world from people who were horrified at what they considered to be an attack by the Germans on innocent civilians. At the time the USA was not involved in the war, having declared itself neutral, but this shock and sense of outrage eventually resulted in the USA joining the war against the Germans and the other Central Powers in 1917.
In addition, the event was used to recruit new soldiers with posters asking people to ‘remember the Lusitania!’ and sign up to fight the Germans.