The event that helped convince the United States to enter World War I was the sinking of the Lusitania. Here's why:
1. The sinking of the Lusitania: This event occurred on May 7, 1915, when a German submarine torpedoed and sank the British ocean liner RMS Lusitania off the coast of Ireland. The ship carried American passengers, and the attack resulted in the deaths of 1,198 people, including 128 Americans. This event generated outrage in the United States and played a significant role in swaying public opinion towards entering the war.
While the other events mentioned (overthrow of the Russian tsar, assassination of Archduke Franz Ferdinand, election of Woodrow Wilson) were important historical events during that time period, it was the sinking of the Lusitania that had a direct impact on the United States' decision to join World War I.
