As of 2014, four U.S. presidents have been successfully assassinated: Abraham Lincoln, James Garfield, William McKinley and John F. Kennedy. A further six presidents have faced failed assassination attempts, including Andrew Jackson, Theodore Roosevelt, Franklin Roosevelt, Harry Truman, Gerald Ford and Ronald Reagan.
As the ultimate symbol of the American republic, nearly every president has faced some form of threat against his life. The United States Secret Service was tasked with the protection of the president following the 1901 murder of McKinley. Since that time, six attempts have been made, but only one has succeeded - the Dallas shooting of John F. Kennedy by Lee Harvey Oswald in 1963.