The immediate causes of armed conflict lay closer to home than the islands of the Pacific. Cuba, once the center of Spain's New World empire and the richest of Spain's remaining possessions, had long suffered from an oppressive colonial system. During the Ten Years' War of 1868–1878 and again in 1895, the Cuban people rebelled against the mother country. Spanish troops forcibly quelled the first insurrection, and in the second their harsh treatment of the rebels intensified. American sympathy for the Cubans mounted as the yellow press in the United States published lurid details of Spanish atrocities. Yet the pressure of popular support for Cuban independence, though increasing, was not in itself sufficient to bring about intervention. Also important was the growing economic stake in the "Pearl of the Antilles." During the thirty years of unrest in Cuba, American capital investments there had risen to $50 million, and trade had mounted to as much as $100 million. To Americans with financial or commercial interests in Cuba, the rebellion threatened disaster, and they urged a speedy resolution of the difficulty. Unlike the yellow press and the jingoes, most businessmen opposed war. They were fearful that armed conflict might interfere with the orderly process of recovery from depression.
As the fate of Cuba became a subject of national attention, McKinley evaluated the forces at work and considered possible responses to them. Lacking complete confidence in his secretary of state, he himself assumed responsibility for developing a policy. Though he kept his own counsel, he did solicit advice and information. Especially important were the reports he received from Fitzhugh Lee, American consul general in Havana, and Stewart Woodford, who had been carefully though belatedly chosen to serve as American ambassador in Madrid. By the time Woodford presented his credentials to the Spanish foreign minister in the fall of 1897, McKinley had determined that neither war nor the annexation of Cuba would serve the national interest. He therefore proposed that he mediate the conflict so as to secure Cuban autonomy under the Spanish crown. A new liberal government came to power in Madrid coincident with Woodford's arrival, and hopes for a settlement ran high.
The response to McKinley's suggestions was disappointing. Although pledging more humane treatment of the rebels, the Spanish regime of Práxedes Mateo Sagasta rejected mediation and, instead of real autonomy, proposed a Cuban legislature dominated by a council of Spanish appointees. Few Americans and certainly none of the rebels could detect in the proposal much more than the promise of conciliation, and promises were not enough. Yet McKinley was a man of prodigious patience. In his annual message of December 1897 he repudiated the idea of annexation and urged that Spain "be given a reasonable chance to realize her expectations and to prove the asserted efficacy of things to which she stands irrevocably committed." Not fully appreciating the warnings that the presidential message also contained, those who favored military intervention were predictably disappointed that McKinley did not take a firmer position.
Carefully worded though it was, the message also produced some unexpected consequences. Enrique Dupuy de Lôme, the Spanish minister in Washington, found it insincere and hypocritical. He wrote his opinions to a friend in Havana, and in the process, he described McKinley as a cheap, vacillating politician. It was a foolish thing to do. A New York-based Cuban junta had been working vigorously for American intervention, and its spies stole the letter. Anticipating that publication of its insulting contents would add strength to the sentiment for intervention, the junta promptly turned a facsimile over to the New York Journal . It appeared on 9 February 1898, and readers were duly enraged by its insolence. Although Dupuy resigned, and the Spanish government forwarded an apology, the harm had been done.
The yellow press and the jingoes were still seething over the de Lôme letter when an even more disturbing communiqué arrived in Washington. McKinley had been concerned with the threat to American lives and property in Cuba, and he had ordered the battleship Maine to Havana. Publicized as a courtesy call to reduce tensions with Spain, the visit was clearly intended as a show of strength. On the night of 15 February the ship exploded and sank with a loss of 266 lives. Shaken by news of the disaster, McKinley insisted on an official investigation. If nothing else, it would take time and help avoid precipitate action. Despite public clamor for military confrontation, he did not believe that American forces were adequately prepared for war. From Congress he asked for, and received, an appropriation of $50 million for national defense, to be spent at his discretion.
McKinley's tendency to procrastinate often left doubts about his intentions, and his tendency to keep his own counsel helped to assure neither Congress nor the American people that he had a clear sense of direction. While the nation awaited the report of the Maine investigation, administration supporters less patient than McKinley gravitated toward the interventionist camp. Senator Redfield Proctor of Vermont, a fair-minded opponent of war, addressed his colleagues for several hours on 17 March, describing in clinical detail the concentration camps he had seen on a recent trip to Cuba. His conclusion that the rebels would not accept Spanish rule and that peace and justice required intervention was a warning to the president that Congress now expected bold action.