Which event led to the United States' involvement in World War I?

The sinking of the Lusitania is the event that significantly swayed public opinion and political sentiment in the United States toward entering World War I. On May 7, 1915, a British ocean liner, the Lusitania, was torpedoed by a German U-boat, resulting in the deaths of nearly 1,200 passengers, including 128 Americans. This tragic event stirred outrage among the American public, leading to demands for the U.S. government to take action against Germany.

Prior to the Lusitania incident, there was a strong isolationist sentiment in the U.S., with many citizens and leaders reluctant to become entangled in European conflicts. However, the loss of American lives and the perception that Germany's unrestricted submarine warfare posed a direct threat to American interests shifted the narrative. Consequently, the sinking of the Lusitania became a pivotal moment that contributed to the U.S. declaration of war against Germany in April 1917.

This incident exemplified the broader issues of maritime rights and the principle of freedom of the seas, which were major factors in the U.S. decision to support the Allied Powers. Additionally, the Lusitania crisis highlighted the way that modern warfare could impact civilians, further influencing America's eventual engagement in the war