The sinking of the Lusitania in 1915 symbolized the growing tensions leading to World War I. The British ocean liner was torpedoed by a German U-boat, resulting in the deaths of nearly 1,200 people, including 128 Americans. This event heightened anti-German sentiment in the United States and contributed to the country's decision to enter the war in 1917. The sinking represented not only a turning point in international relations but also underscored the dangers of unrestricted submarine warfare, influencing public opinion and shifting political attitudes towards involvement in the conflict.