Abraham Lincoln - Lincoln was shot in the head while watching a play on April 14, 1865. His assassin, John Wilkes Booth escaped and was later shot and killed.Conspirators who helped plan Lincoln's assassination were found guilty and hung. Lincoln died on April 15, 1865.
James Garfield - Charles J. Guiteau, a mentally disturbed government office seeker, shot Garfield on July 2, 1881. The president did not die until September 19th of blood poisoning. This was related more to the manner in which the physicians attended to the president than to the wounds themselves. Guiteau was convicted of murder and hanged on June 30, 1882.
William McKinley - McKinley was shot two times by anarchist Leon Czolgosz while the president was visiting the Pan-American Exhibit in Buffalo, New York on September 6, 1901. He died on September 14, 1901. Czolgosz stated that he shot McKinley because he was an enemy of working people. He was convicted of the murder and electrocuted on October 29, 1901.
John F. Kennedy - On November 22, 1963, John F. Kennedy was mortally wounded while riding in a motorcade in Dallas, Texas. His apparent assassin, Lee Harvey Oswald, was killed by Jack Ruby before standing trial. The Warren Commission was called to investigate Kennedy's death and found that Oswald had acted alone to kill Kennedy. Many argued, however, that there was more than one gunman, a theory upheld by a 1979 House Committee investigation. The FBI and a 1982 study disagreed. Speculation continues to this day.
Andrew Jackson - On January 30, 1835, Andrew Jackson was attending a funeral for Congressman Warren Davis. Richard Lawrence, attempted to shoot him with two different derringers, each of which misfired. He was tried for the attempted assassination but was found not guilty by reason of insanity. He spent the rest of his life in an insane asylum.
Theodore Roosevelt - An assassination attempt was actually not made on Roosevelt's life while he was in the office of president. Instead, it occurred after he had left office and decided to run for another term against William Howard Taft. While campaigning on October 14, 1912, he was shot in the chest by John Schrank, a mentally disturbed New York saloonkeeper. Luckily, Roosevelt had a speech and his spectacle case in his pocket that slowed down the .38 caliber bullet. The bullet was never removed but allowed to heal over.
Franklin Roosevelt - After giving a speech in Miami on February 15, 1933, Giuseppe Zangara shot six shots into the crowd. None hit Roosevelt though the Mayor of Chicago, Anton Cermak was shot in the stomach. Zangara blamed wealthy capitalists for his plights and those of other working people. He was convicted of attempted murder and then after Cermak's death due to the shooting he was retried for murder. He was executed by electric chair in March, 1933.
Harry Truman - On November 1, 1950, two Puerto Rican nationals attempted to kill President Truman to bring attention to the case for Puerto Rican independence. The President and his family were staying at the Blair House across from the White House and the two attempted assassins, Oscar Collazo and Griselio Torresola, tried to shoot their way into the house. Torresola killed one and wounded another policeman while Collazo wounded one policeman. Torresola died in the gunfight. Collazo was arrested and sentenced to death which Truman commuted to life in prison. Carter freed Collazo from prison in 1979.
Gerald Ford - Ford escaped two assassination attempts, both by women. First on September 5, 1975, Lynette Fromme, a follower of Charles Manson, pointed a gun at him but did not fire. She was convicted of attempting to assassinate the president and sentenced to life in prison. The second attempt on Ford's life occurred on September 22, 1975 when Sara Jane Moore fired one shot that was deflected by a bystander. Moore was trying to prove herself to some radical friends with the assassination of the president. She was convicted of attempted assassination and sentenced to life in prison.
Ronald Reagan - On March 30, 1981, Reagan was shot in the lung by John Hinckley, Jr. Hinckley hoped that by assassinating the president, he would earn enough notoriety to impress Jodie Foster. He also shot Press Secretary James Brady along with an officer and a security agent. He was arrested but found not guilty by reason of insanity. He was sentenced to life in a mental institution.
One fascinating sidenote to presidential assassinations and deaths in office is Tecumseh's Curse whereby presidents starting with William Henry Harrison who were elected in a year ending with a zero were assassinated or died while in office. The curse ended with Ronald Reagan. Read this article to learn more about the history of the curse.