The phrase "Remember the Maine" is associated with the Spanish-American War, which began in 1898. The slogan emerged after the USS Maine, an American battleship, exploded in Havana Harbor in February 1898. Many Americans blamed Spain for the explosion, although the exact cause remains unclear. This sentiment fueled public outrage and sentiment in favor of military intervention, ultimately leading the U.S. to declare war on Spain. The conflict resulted in the U.S. acquiring territories like Puerto Rico, Guam, and the Philippines, marking a significant shift in its role as an emerging global power.