In 1890 president McKinley changed the U.S. tariff policy. The McKinley tariff Act of 1890 admitted Cuban sugar to the U.S. duty free. This soon led to even worse than the poor factory conditions than the Cubans had before. In 1895 the Cubans started a revolt against the Spanish. Enrique Dupuy de Lome was the Spanish minister to the U.S. He wrote what is called the "De Lome letter" to a private friend in Cuba, criticizing President McKinley. Soon the American press got hold of the letter and printed it everywhere.
President McKinley sent the U.S.S. Maine to protect the Cubans in 1896. When the U.S.S. main reached Cuba on February 15 1898 there was an explosion and the ship was sunk. It was the sinking of the U.S.S. Maine in Cuba, that the U.S. declared war with Spain. President McKinley declared war with Spain on February 20 1898. On May first U.S. naval commander George Dewey arrives in Manila bay in the Philippines. In that battle at Manila bay there were over 300 Spanish deaths and 12 American death.
The war with Spain would not go on for long. The American battle ship Oregon which went from Puget Sound Washington to Cuba sunk the entire Spanish fleet in Santiago harbor. Soon after the U.S. captured Puerto Rico. Before the summer of 1898 was finished the Spanish land forces in the Philippines surrendered. In a peace treaty signed in October of that year the U.S. agreed to pay Spain 20 million form Cuba, Puerto Rico, the Philippines, and the island of Guam. After the summer of 18998 the U.S. became a colonial power.