On what date did the U.S. declare war on Spain?

The United States declared war on Spain on April 25, 1898. Congress formally declared that a state of war had existed between the two countries since April 21, making April 25 the date of the enacted declaration.

The timing can be confusing because several important steps occurred within days. Congress passed a joint resolution on April 19 calling for Cuban independence and authorizing military action. President William McKinley signed it on April 20, and the United States began a naval blockade of Cuba on April 22. Spain treated the American ultimatum as an act of war and declared war on April 23.

The American declaration came after the destruction of the battleship USS Maine in Havana harbor, intense public pressure, and the continuing Cuban revolt against Spanish rule. The war ended with the Treaty of Paris on December 10, 1898, which transferred Spain's remaining major overseas possessions to American control and ended Spanish rule in Cuba.