HOUSTON, United States

The attempted assassination of Donald Trump at a Pennsylvania campaign rally on Saturday adds to a surprisingly long list of sitting and former US presidents who have been victims of either assassinations or assassination attempts throughout American history.

The last time a US president was injured in an assassination attempt occurred 43 years ago, during Ronald Reagan's first term in office. He was shot by John Hinckley, Jr. on March 30, 1981, outside a Hilton Hotel in Washington, DC, resulting in a broken rib and punctured lung. Reagan underwent emergency surgery, recovered from his injuries, and went on to win reelection to his second term in the White House.

The most well-known assassination of an American president in modern times was the shooting of John F. Kennedy on Nov. 22, 1963, in Dallas, Texas. Kennedy was riding in a presidential motorcade in an open-top limousine when he was shot in the back of the head and killed by Lee Harvey Oswald from the sixth floor of the Texas School Book Depository.

Kennedy was one of four US presidents assassinated. The other three are Abraham Lincoln, James Garfield, and William McKinley, according to the American public television network PBS.

Lincoln was assassinated on April 15, 1865, less than one week after the Civil War had officially ended. He was attending a play at Ford's Theater in Washington, DC when John Wilkes Booth fatally shot him in the back of the head.

Garfield was shot twice in the back on July 2, 1881, by Charles Guiteau as the president was preparing to board a train at the Washington, DC train station. Garfield survived for nearly two months after the shooting, but eventually died of his wounds.

McKinley was shot twice in the chest at point-blank range on Sept. 6, 1901, by Leon Czolgosz while greeting visitors at the Pan-American Exposition in Buffalo, New York. The president survived the initial shooting but died eight days later after succumbing to gangrene caused by the wounds.

Assassination attempts on American presidents date back nearly two centuries.

The first took place on Jan. 30, 1835, when Richard Lawrence tried to shoot President Andrew Jackson after he left a congressional funeral in the Capitol building, but both of his guns misfired.

Theodore Roosevelt was shot in the chest on Oct. 14, 1912, by John Schrank in Milwaukee, Wisconsin, as he was headed to a campaign speech in his bid for re-election. Historical records show that a 50-page text of Roosevelt's speech in his breast pocket combined with a metal glasses case slowed the bullet and saved his life.

On Feb. 15, 1933, Franklin D. Roosevelt was shot at by Giuseppe Zangara after giving a speech in Miami, Florida, just 17 days before his first presidential inauguration. The five bullets fired missed the president-elect, and Roosevelt was not injured during the assassination attempt. However, the shots fatally killed Chicago Mayor Anton Cermak.

Harry Truman was shot at by two Puerto Rican nationalists on Nov. 1, 1950, during the renovation of the White House. The president escaped injury, but a police officer was killed during the assassination attempt.

Gerald Ford faced two assassination attempts in 1975. The first happened on Sept. 5 on the grounds of the state capitol in Sacramento, California, where Lynette Fromme's gun misfired. The second occurred 17 days later when Ford was visiting San Francisco on Sept. 22. Sara Jane Moore fired at Ford but missed. Ford was not injured in either assassination attempt.

On May 10, 2005, George W. Bush was giving a speech at Freedom Square in Tbilisi, Georgia when Vladimir Arutyunian threw a live grenade toward the podium. The grenade did not detonate and the president was not injured, but during his arrest, Arutyunian killed an Interior Ministry agent.

Oscar Ramiro Ortega-Hernandez shot at least seven bullets at the White House on Nov. 11, 2011, during Barack Obama's first term in office. Neither the president nor the first lady were on the grounds during the attempted assassination.

There have also been two high-profile incidents of an assassination and an attempted assassination of politicians who were not presidents.

On June 5, 1968, Robert F. Kennedy, brother of President John F. Kennedy, was fatally shot by Sirhan Sirhan at the Ambassador Hotel in Los Angeles. RFK was a leading candidate in the 1968 Democratic Party presidential primaries.

Former Alabama Governor George Wallace was a leading candidate for the 1972 Democratic presidential primaries when he was shot four times by Arthur Bremer while campaigning at a shopping center in Laurel, Maryland. Wallace was struck in the abdomen and chest and was left paralyzed from the waist down for the rest of his life. The attempted assassination and subsequent injuries put an end to his presidential bid.