Which incident led the United States to declare war on Spain in 1898?

The incident that led the United States to declare war on Spain in 1898 was the explosion of the USS Maine in Havana Harbor. This event garnered significant media attention and public outrage, largely fueled by sensationalist journalism known as "yellow journalism." The explosion was interpreted by many Americans as an attack by Spain on U.S. interests, despite the lack of conclusive evidence regarding the cause of the explosion. The rallying cry "Remember the Maine!" became a powerful slogan that encapsulated the public sentiment urging the government to respond militarily.

In contrast, while a rebellion was indeed occurring in the Spanish Philippines, it was the USS Maine incident that directly triggered U.S. involvement and the declaration of war. The Panama Canal's construction and the signing of the Roosevelt Corollary occurred later and were not related to the immediate cause of the war with Spain. The events surrounding the USS Maine were pivotal in shaping U.S. foreign policy and marked the beginning of American imperialism in the late 19th century.