Theodore Roosevelt October 27, 1858 – January 6, 1919) was an American statesman, author, explorer, soldier, naturalist, and reformer who served as the 26th President of the United States from 1901 to 1909. As a leader of the Republican Party during this time, he became a driving force for the Progressive Era in the United States in the early 20th century. Following the assassination of President McKinley in September 1901, Roosevelt, at age 42, succeeded to the office, becoming the youngest United States President in history.

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