U.S. Marines Land In Guantanamo Bay

On June 10, 1898, U.S. Marines landed at Guantánamo Bay. For the next month, American troops fought a land war in Cuba that resulted in the end of Spanish colonial rule in the Western Hemisphere. Cuban rebels had gained the sympathy of the American public while the explosion and sinking of the U.S.S. Maine, widely blamed on the Spanish despite the absence of conclusive evidence, further boosted American nationalistic fervor.

Popular demand for intervention in the Cuban-Spanish conflict led Congress to pass resolutions demanding the withdrawal of Spanish armed forces from Cuba, authorizing U.S. aid to effect this, and promising American support for Cuban self-rule. Spain declared war against the United States on April 24, 1898, and the United States promptly replied with a counter-declaration.

http://memory.loc.gov/ammem/today/jun10.html