Question

Name the youngest U.S. Vice President to be sworn in as President upon the death of the President. He served in the 20th century.

Answer 1

Answer: The youngest U.S. Vice President to be sworn in as President upon the death of the President in the 20th century was Theodore Roosevelt. He became President on September 14, 1901, following the assassination of President William McKinley. Theodore Roosevelt was 42 years old at the time.