William McKinley was the last President to have fought in the Civil War, and the only one to have fought as a private. He led the US during its last period of significant expansion, acquiring a number of territories (including Puerto Rico, Cuba, and the Phillipines) by defeating Spain in the Spanish-American War. During his first term, the United States also annexed the Kingdom of Hawaii. The economy boomed under McKinley, and he was elected to a second term. McKinley became the 3d US President to be assassinated in September, 1801. He was shot by an American anarchist. His Vice-President, Theodore Roosevelt, became President.