History of Oceania

What event made us enter World War 1?

The event that caused the US to enter World War I was the sinking of the British passenger liner RMS Lusitania by the Imperial German Navy on May 7, 1915. The ship was torpedoed and sunk off the coast of Ireland with the loss of 1,198 lives, including over 120 American citizens. The sinking of the Lusitania caused a wave of outrage in the US and was seen as a major violation of international law. It also brought America closer to joining the war on the side of the Allies.