On May 1st, 1915 the British ocean liner named the Lusitania was making its 202nd journey across the Atlantic Ocean from Liverpool to New York. On May 7th, off the coast of Ireland on its way to its destination, the ship was fired by a torpedo from a German U-boat. The boat primarily carried people and other goods. On board, there was 1,959 people and of those people, 1,198 people died, including 128 Americans. The boat had two explosions. The first explosion was from the torpedo the German U-boat fired. The second explosion came from munitions that the boat was also carrying. The second explosion was what made the ship sink. 

This scenario was mostly the reason why we decided to enter WWI.  After the sinking of the Lusitania, a bunch of newspapers published warnings that if British or Allied ships were to cross in war zones, they were risking attack by the Germans. In late March, Germany sunk 4 more merchant ships. On April 2nd, 1917, the U.S. declared war against Germany. This was the start beginning of the U.S World War.