Theodore Roosevelt, 26th President of the U.S. (1901-1909)

In 1901, Theodore Roosevelt became the 5th Vice President to assume the presidency upon the death of the elected president.  In this case, the assassination of William McKinley, the third U.S. President to be assassinated, led to Roosevelt becoming president. At 42 years old, Theodore Roosevelt remains, as of 2018, the youngest person to serve as President of the United States.

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