This created an outcry to intervene and end the suffering in Cuba. The effect of public opinion on United States policy began to increase from this period on, and was a substantial reason for the decisions that were to be made in the immediate future concerning Cuba. Also it was known that the Spaniards had seemingly tricked America, as written in an intercepted letter composed by the Spanish minister to the United States, Enrique Dupuy de Lome. This letter denounced the reforms that Madrid had put forth to calm Cuba, and personally insulted President McKinley.
There were also political and economical considerations concerning Cuban intervention. The political issue, locally, was the upcoming Presidential election. The United States publicly wanted war. This made McKinley's fight for peace seem comparable to John Adams' fight for peace which caused him to lose the third Presidential election of the United States to Thomas Jefferson. So McKinley knew that he had to satisfy the public someway, perhaps that satisfaction would come with an abandonment of peace. Economic issues pointed to McKinley's affiliation with big business. With the United States owning land in Cuba that was available for business, this issue could have persuaded McKinley to make the decisions that he did.
After it had become known that the supposed Spanish reforms on Cuba had no effect, the United States deployed the battleship U.S.S. Maine to Havana on January 24, 1898 as a symbolic gesture. After the interception of the de Lome letter, on February 15th, someway or another the U.S.S. Maine was sunk in the harbor of Havana. Even after this infuriating event McKinley still tried one last effort with diplomacy. McKinley demanded armistice for the fighting in Cuba, independence for the Cuban people, and recognition of United States intervention. These demands were hastily met by the Spanish government, and on April 11th President McKinley asked congress for military intervention.