Tensions within the Spanish empire gave T.R. his opening. Cuba had been waging a war for independence from Spain since 1895, and the Philippines, another Spanish possession, had been in open insurrection since 1896. When, in early 1898, a riot by Spanish loyalists in Havana endangered American lives, the battleship USS Maine steamed toward Cuba to maintain order. On 15 February 1898, the Maine exploded in Havana Harbor under suspicious circumstances. Back home in the United States, the sinking of the Maine brought cries for war to a fever pitch. Ten days later, convinced that war with Spain was inevitable, T.R. ordered Commodore George Dewey to intercept the Spanish fleet at Manila, at the same time redoubling his efforts to convince President McKinley to declare war. On 11 April 1898, the president finally gave in, asking Congress to authorize a military intervention in Cuba.
T.R. could not have been happier. He must have inherited his father's shame at having shirked Civil War duty. Even before war broke out, T.R (who was now 40 years old) made his goals very clear: if war broke out, he was going to fight. This was an opportunity he was not going to miss. He used his connections to assemble a volunteer cavalry regiment, stocked it with the cream of New York society, and led his men off to battle.
It was a strange war. T.R. and his Rough Riders landed in Cuba on 22 June 1898, and were out of combat ten days later. By August they were home and the war was over. Dewey had disabled the Spanish fleet on 1 May, effectively ruining Spain's chances from the start. As T.R. would later reflect, "the only trouble was that there was not enough war to go around." Still, it was more than enough to make him a national hero. At the battle of San Juan Heights, T.R. led his men in a daring charge up Kettle Hill, exposing himself to enemy fire in the process. His brave exploits were reported back in the United States by the newspapermen who served in his regiment. When T.R. returned to New York, he was greeted by masses of cheering citizens, asking him to run for governor.