What event catalyzed the United States’ entry into World War I?

The sinking of the Lusitania played a pivotal role in catalyzing the United States' entry into World War I due to its impact on public opinion and governmental policy. When the German U-boat sank the British passenger ship Lusitania in May 1915, it resulted in the deaths of 1,198 passengers, including 128 Americans. This event heightened tensions between Germany and the United States, as many Americans were outraged by the attack on a ship, believed to be carrying civilians and refugees.

The incident galvanized anti-German sentiment in the U.S. and fueled calls for intervention in the war. While the U.S. government initially maintained a stance of neutrality, the sinking of the Lusitania and subsequent attacks on American merchant ships contributed to a shift in public and political attitudes. Ultimately, these incidents, coupled with other factors like unrestricted submarine warfare by Germany, led to the U.S. declaring war on Germany in April 1917.

In contrast, the attack on Pearl Harbor occurred during World War II, the bombing of Hiroshima was one of the concluding events of World War II, and the signing of the Treaty of Versailles took place after World War I had ended, making these options unrelated to the specific event that pushed the