What crystallized American opinion at the beginning of World War 1?

At the beginning of World War I, American opinion was largely characterized by a desire for neutrality and isolationism, influenced by the country's recent experiences in the Spanish-American War and a general aversion to European conflicts. Many Americans sympathized with the Allied powers, particularly Britain and France, due to cultural ties and economic interests, but there was also significant support for the Central Powers, especially among German and Irish immigrant communities. The sinking of the Lusitania in 1915 and other provocations, such as the Zimmermann Telegram in 1917, gradually shifted public sentiment toward supporting intervention. Ultimately, a combination of economic interests, humanitarian concerns, and a growing belief in America's role on the global stage crystallized public opinion in favor of joining the war.