The Battle of San Juan Hill, also known as the Battle for the San Juan Heights, was a major battle of the SpanishAmerican War fought between an American force under the command of William Rufus Shafter and Joseph Wheeler against a Spanish force led by Arsenio Linares y Pombo. The battle proved to be one of the most significant battles of the war and, along with the Siege of Santiago, a decisive battle in deciding the fate of the United States Army campaign in Cuba. The American forces, outnumbering the Spanish defenders 16-to-one, charged upon the heights and dispersed the Spanish after suffering heavy casualties.

Tensions between Spain and the United States worsened over Spanish behavior during their efforts to quell the Cuban War of Independence, with many Americans being agitated by exaggerated reports of Spanish atrocities against the Cuban population. In January 1898, fearing the fate of American interests in Cuba due to the war, the cruiser USS Maine was dispatched to protect them. Less than a month later, the cruiser exploded while lying at anchor in Havana harbor, killing 261 sailors onboard and inflaming American opinion, with Spain being portrayed as the culprit in the American media without conclusive evidence. Two months later, war was declared.

The Americans, after already landing troops in the Battle of Guantnamo Bay, moved inland to seek a decisive encounter with the Spanish forces. Both sides drew blood at the Battle of Las Guasimas, with the Spanish moving to defend the strategically valuable San Juan Heights from the Americans. A week later, a significantly larger American force, including the famed 'Rough Riders', moved to clear the heights of the Spanish. After enduring artillery fire which inflicted heavy casualties, the Americans charged up the hill and dispersed the Spanish, suffering even more heavily in the process. The fight for the heights proved to be the bloodiest and most famous battle of the war.

The battle also proved to be the location of the "greatest victory" for the Rough Riders, as stated by the press and its new commander, Theodore Roosevelt, who eventually became vice president and later president of the United States, and who was posthumously awarded the Medal of Honor in 2001 for his actions in Cuba and became the only U.S. president to receive the award. The Americans won another engagement at El Caney the same day, with both battles highlighting the bravery and skill of the American/Cuban forces, as well as the Spanish defenders. Following the surrender of the Spanish army at Santiago, they agreed to depart Cuba, ending over four centuries of Spanish rule.

The Spanish–American War (April 21 – August 13, 1898) was period of armed conflict between Spain and the United States. Hostilities began in the aftermath of the internal explosion of USS Maine in Havana Harbor in Cuba, leading to U.S. intervention in the Cuban War of Independence. The war led to the U.S. emerging predominant in the Caribbean region, and resulted in U.S. acquisition of Spain's Pacific possessions. It led to U.S. involvement in the Philippine Revolution and later to the Philippine–American War.

The main issue was Cuban independence. Revolts had been occurring for some years in Cuba against Spanish colonial rule. The U.S. backed these revolts upon entering the Spanish–American War. There had been war scares before, as in the Virginius Affair in 1873. But in the late 1890s, American public opinion swayed in support of the rebellion due to reports of concentration camps set up to control the populace. Yellow journalism exaggerated the atrocities to further increase public fervor and to sell more newspapers and magazines.The business community had just recovered from a deep depression and feared that a war would reverse the gains. Accordingly, most business interests lobbied vigorously against going to war. President William McKinley ignored the exaggerated news reporting and sought a peaceful settlement. However, after the United States Navy armored cruiser Maine mysteriously exploded and sank in Havana Harbor on February 15, 1898, political pressures from the Democratic Party pushed McKinley into a war that he had wished to avoid.

On April 20, 1898, McKinley signed a joint Congressional resolution demanding Spanish withdrawal and authorizing the President to use military force to help Cuba gain independence. In response, Spain severed diplomatic relations with the United States on April 21. On the same day, the U.S. Navy began a blockade of Cuba. Both sides declared war; neither had allies.

The 10-week war was fought in both the Caribbean and the Pacific. As U.S. agitators for war well knew, U.S. naval power would prove decisive, allowing expeditionary forces to disembark in Cuba against a Spanish garrison already facing nationwide Cuban insurgent attacks and further devastated by yellow fever. The invaders obtained the surrender of Santiago de Cuba and Manila despite the good performance of some Spanish infantry units, and fierce fighting for positions such as San Juan Hill. Madrid sued for peace after two Spanish squadrons were sunk in the battles of Santiago de Cuba and Manila Bay, and a third, more modern fleet was recalled home to protect the Spanish coasts.The war ended with the 1898 Treaty of Paris, negotiated on terms favorable to the U.S. It ceded ownership of Puerto Rico, Guam, and the Philippine islands from Spain to the U.S. and granted the U.S. temporary control of Cuba. The cession of the Philippines involved payment of $20 million ($620 million today) to Spain by the U.S. to cover infrastructure owned by Spain.The defeat and loss of the Spanish Empire's last remnants was a profound shock to Spain's national psyche and provoked a thorough philosophical and artistic reevaluation of Spanish society known as the Generation of '98. The United States meanwhile not only became a major power, but also gained several island possessions spanning the globe, which provoked rancorous debate over the wisdom of expansionism.