The sinking of the Lusitania with United States citizens aboard helped bring the United States into the war.

The sinking of the Lusitania was a significant factor that contributed to the eventual entry of the United States into World War I. The Lusitania, a British ocean liner, was sunk by a German submarine on May 7, 1915, off the coast of Ireland. The attack resulted in the deaths of nearly 1,200 people, including 128 Americans.

This event played a crucial role in shaping public opinion in the United States and swaying sentiments toward intervention in the war. The sinking of the Lusitania heightened anti-German sentiment and increased calls for the United States to take a more active role in the conflict. While the U.S. did not enter the war immediately following the Lusitania's sinking, it became a contributing factor that, combined with other incidents, eventually led to President Woodrow Wilson asking Congress to declare war on Germany in April 1917.