How did the sinking of the Lusitania affect American opinion about World War I?

The sinking of the British ocean liner Lusitania by a German U-boat on May 7, 1915, was a pivotal moment that significantly shifted American public sentiment, though it did not immediately lead to war.12

The attack, which resulted in the deaths of 1,198 people—including 128 U.S. citizens—aroused a wave of intense indignation and outrage across the United States. Despite this public anger and the expectation from many that the U.S. would declare war, the government under President Woodrow Wilson remained committed to a policy of neutrality for another two years.132

While the Lusitania incident did not trigger an immediate military response, it brought the United States to the brink of conflict and served as a critical factor in the eventual decision to enter World War I. The U.S. government ultimately cited German submarine warfare as a primary justification when it officially declared war in 1917.513