Setting the scene
By 1898, Cuba had been fighting Spain for independence since 1895, with brutal Spanish reconcentration camps killing 200,000 Cubans. American newspapers, led by Hearst and Pulitzer, published sensational stories of Spanish atrocities—yellow journalism. The US had economic interests in Cuban sugar and strategic interest in a Caribbean canal. On February 15, 1898, the USS Maine exploded in Havana Harbor, killing 266 Americans. Though the cause was likely accidental, newspapers blamed Spain with the slogan 'Remember the Maine!'
What happened
The Spanish-American War began April 21, 1898. The US Navy under Commodore Dewey destroyed the Spanish fleet at Manila Bay in the Philippines on May 1 without losing a man. In Cuba, Teddy Roosevelt's Rough Riders charged San Juan Hill on July 1. The war lasted 10 weeks. Spain, weakened and unprepared, sued for peace after losing its fleets. The Treaty of Paris, signed December 10, 1898, ended 400 years of Spanish empire.
Why it still matters
The US emerged as a world power, acquiring Puerto Rico, Guam, and the Philippines for $20 million, and occupying Cuba (independent in 1902). The war marked America's shift from isolationism to imperialism, leading to the Philippine-American War (1899-1902) that killed 200,000 Filipinos. It established the US as a Pacific power and led to the Panama Canal. The war's easy victory created American confidence in military intervention abroad, a precedent for 20th-century foreign policy. It also launched Roosevelt's political career to the presidency.
Background
Spain ceded territories including Puerto Rico and the Philippines.