John F. Kennedy was the one.
John F. Kennedy at 46, followed by James Garfield at 49. They were both assassinated in office. The youngest president to die a natural death was James K. Polk who died of cholera at 53.
John F. Kennedy was the 35th US President.
US president John F. Kennedy was shot while riding in a open limousine,as it drove down Elm Street, through Dealey Plaza in Dallas, Texas on November 22nd, 1963.
Theodore Roosevelt was sworn in as the youngest US President at age 42 as a result of the assassination of President William McKinley, who was shot and died on 14 September 1901.
As of 2017, the youngest US president was Theodore Roosevelt, who was only 42 when he took office.
Theodore Roosevelt
Kennedy was the youngest elected US president.
Technically John F. Kennedy was elected the youngest but the youngest president in office was Roosevelt. (Roosevelt was elected Vice President in 1900 and became President when President William McKinley was assassinated.)
Thirty eight
bill clinton
US President Kennedy was assassinated in in Dealey Plaza in Dallas, Texas on November 22, 1963. He had been traveling with his wife and other politicians in an open car motorcade on the way to the Dallas airport when he was hit with gunfire that mortally wounded him. The governor of Texas was also wounded by the assassination bullets.
Theodore Roosevelt was the Vice President under William McKinley and was the youngest president to hold officer when McKinley was assassinated. John F. Kennedy was youngest president elected to office.