Assassination attempts and plots on Presidents of the United States have been numerous: more than 20 attempts to kill sitting and former presidents, as well as the Presidents-elect, are known. Four sitting presidents have been killed, all of them by gunshot: Abraham Lincoln (the 16th President), James A. Garfield (the 20th President), William McKinley (the 25th President) and John F. Kennedy (the 35th President). Two presidents were injured in attempted assassinations, also by gunshot: Theodore Roosevelt (the 26th President) and Ronald Reagan (the 40th President). With the exception of Lyndon Johnson, every president's life since John F. Kennedy has been threatened with assassination.