After the declaration of war in April, the Spanish fleet was quickly sent to Cuba under Admiral Pascual Cervera. The ten boats in Cervera's command were in truly horrible condition. Of the 10 rotting ships, only 7 actually made it to Cuba. The other 3 had to be abandoned along the way. Despite the rather pathetic nature of the Spanish fleet, Americans on the Eastern seaboard became very frightened of a potential Spanish invasion of the US. Eventually, Cervera's decrepit fleet limped into Santiago harbor in Cuba, where they were blockaded by the US Navy.
With the Spanish fleet contained, the US planned a landing of the US Army, which would then attack the Spanish from the rear. The landing was made under the command of General William R. Shafter, a veteran of the Civil War. Shafter was so fat and ill with gout that his men had to carry him around on a door; he matched that dubious physical condition with an uninspiring talent at logistics and strategy. The US had absolutely no experience fighting in the tropics, and the unprepared US Army showed up in Cuba with vast supplies of wool clothing.
Better equipped for the job in Cuba were the famous "Rough Riders", a ragtag group of volunteers fighting for the US. Most of them were cowboys, but all kinds of colorful characters, from the wealthy thrill-seekers to former criminals, found their way into the unit, which was commanded by Colonel Leonard Wood. The Rough Rider officer best remembered, however, was no doubt Lieutenant Colonel Theodore Roosevelt. Roosevelt, ever a fan of strenuous activity and competition, had resigned his post as Assistant Secretary of the Navy to fight in the war. Roosevelt had absolutely no military experience, and the military had even had to bend some rules to let him in with his terrible nearsightedness. Keeping enough glasses on hand for Roosevelt, so he could still see if the ones he was wearing broke, was a difficult task.
US forces landed at Santiago without having to fight the Spanish, as the Spanish proved even more confused than the Americans. On July 1, 1898, the first major land battles of the war were fought at El Caney and at San Juan Hill. The Battle of San Juan Hill was famous because the "Rough Riders", walking since many of their horses did not arrive in Cuba, charged up the hill. The battle was soon immortalized in a Frederic Remington painting (mentioned earlier in the Commentary on Yellow Journalism. The US won both battles, though the "Rough Riders" suffered heavy losses. Roosevelt, for his part, enjoyed himself immensely, and even shot a Spanish soldier. These battles proved decisive.
Now that the war was almost over, the US quickly moved to occupy Spanish-owned Puerto Rico. On August 12, 1898, the Spanish signed an armistice ending the fighting.
Despite the "Rough Riders" famous legacy, both they and the US Army were so disorganized and bumbling that only about half of them made it from Tampa Bay, Florida to the landing at Santiago. And although the "Rough Riders" were organized as a cavalry unit, very few of their horses actually made it to Cuba. As a result, most of the "Rough Riders" actually walked during the war. That the war went so well for the US was virtually a miracle given the disorganization and poor planning that plagued the American military effort.
Along with the heroic exploits of the "Rough Riders", two black regiments played a crucial role in winning San Juan Hill. The charge up the hill itself was made on foot, since so few horses had made it to Cuba.
After the battles of El Caney and San Juan Hill, Admiral Cervera, commanding the Spanish fleet, was ready to surrender. With his old ships rotting and the land army facing defeats, Cervera knew he could not win. Nevertheless, Spanish leaders ordered him to continue fighting to preserve Spanish honor. By July 3, continuing the trend of US naval dominance, his fleet had been utterly destroyed. In the naval battles, 500 Spanish sailors lost their lives while only 1 American died.
When it seemed like the war would be over soon, the US moved quickly to send forces into Spanish-controlled Puerto Rico, and took the island with minimal conflict. The American forces, under General Nelson A. Miles, were welcomed by the Puerto Ricans as liberators. But liberation was far from what the US had in store for Puerto Rico. Since it was not bound by the Teller Amendment in Puerto Rico, the US could keep the island as a colony.
The armistice came just in time for the US. Although the US was defeating the Spanish army, disease was coming close to defeating the US Army. Malaria, typhoid, dysentery, and yellow fever were plaguing American troops who were fighting in the tropics for the first time. In all, while the Spanish only killed about 400 American soldiers, around 5,000 US soldiers died from disease.
Walter Reed, a pathologist and biologist working for the US Army, began groundbreaking work into the causes of yellow fever that began as a result of the Spanish-American War. Previously, it had been believed that the fever was spread through material like clothing and bedding. Wood discovered that yellow fever was actually caused by a certain mosquito's bite. Although Wood's work came too late to save American lives in the Spanish-American War, his research beginning during the war led to a better understanding of yellow fever, which was later practically eliminated in Cuba and Latin America by systematically destroying mosquito breeding and nesting areas.