Final answer:
American citizens were enraged by the USS Maine's explosion, influenced by yellow journalism that blamed Spain, leading to the rallying cry 'Remember the Maine, to Hell with Spain!' President McKinley ordered an investigation and prepared for war, which Congress supported, ultimately resulting in the Spanish-American War.
Step-by-step explanation:
After the explosion of the USS Maine on February 15, 1898, American citizens were outraged and reacted strongly to the event. They were swayed by the sensational headlines in U.S. newspapers, fueled by yellow journalism, which immediately blamed Spain for the tragedy. 'Remember the Maine, to Hell with Spain!' became a popular rallying cry.
These headlines and public sentiment influenced policy as President William McKinley, who had initially sought to avoid war, ordered an investigation into the explosion and subsequently requested $50 million from Congress to prepare for potential conflict. Congress quickly passed the bill, and after an investigation suggested an external cause (likely a Spanish mine) for the explosion, the United States declared war on Spain, leading to the Spanish-American War. However, it is worth noting that more recent examinations indicate the explosion was likely accidental, related to a combustion of coal or a munitions issue internal to the ship.