U.S. Presidents Abraham Lincoln, James Garfield, William McKinley and John F. Kennedy all died in office as the result of assassination. Presidents William Henry Harrison, Zachary Taylor, Warren G. Harding and Franklin D. Roosevelt died in office of natural causes.
John Wilkes Booth, a Confederate sympathizer, killed President Lincoln on April 14, 1865, as part of a larger attempt to decapitate the American government in the waning days of the American Civil War. Charles Guiteau, a mentally unstable lawyer and preacher, shot Garfield on July 2, 1881, because he believed that the president should have offered him the post of Ambassador to France. Leon Czolgosz, an anarchist, assassinated President McKinley on Sept. 6, 1901, because he believed that the president was a symbol of oppression. Lee Harvey Oswald shot John F. Kennedy on Nov. 22, 1963, for reasons that remain ambiguous since he was killed two days after he had killed Kennedy.
William Henry Harrison's death on April 4, 1841, came as the result of a cold that deepened to pneumonia, pleurisy and septicemia as a result of overwork. He was the first president to die in office. Zachary Taylor died on July 9, 1850, of a digestive ailment, perhaps cholera, brought on by consuming large amounts of cherries, iced milk and water. Warren G. Harding died of a heart attack on Aug. 2, 1923. Franklin D. Roosevelt died of a stroke on April 12, 1945, after years of ill health and overwork.