The Most Widely Believed Conspiracy Theories in US History

Conspiracy theorists: Call them birthers, deathers or conspiracists. There are many, people who buy into these popular conspiracy theories, which is why they are the most believed conspiracy theories in US history. Many conspiracy theorists have argued that NASA never landed on the moon, the 9/11 and Pearl Harbor attacks were allowed to happen by the US Government, and that President Barack Obama is actually from Kenya. There are a number of other conspiracy theories, but these are the most accepted among theorists.

If these US conspiracy theories sound outlandish, they are only the tip of the iceberg. When it comes to the wildest conspiracy theories presented in modern times, these ones top the list. Hours of time and thousands of dollars have been spent to publicize, prove and debunk these conspiracy theories in American history that deal with everything from alien autopsies at Area 51 to the assassination of President John F. Kennedy.

What are some of the most widely believed conspiracy theories in US history? Look here and see for yourself.


  • 9/11
    Video: YouTube

    Some people (occasionally known as "Truthers") believe that the 9/11 terrorist affront that killed 3,000 Americans on September 11, 2001, were actually orchestrated by the United States government or a group other than al Qaeda. Believers of the conspiracy argue the World Trade Center's Twin Towers fell and continued to burn in the aftermath in a way that suggests it was a controlled demolition.

    Others argue the United States government was aware of 9/11 prior to the event and allowed them to happen by declining to intervene. This theory was mentioned in the Michael Moore documentary Fahrenheit 9/11, especially the idea that then-President George W. Bush was supposedly briefed on the plans for offense and chose to ignore them.

  • John F. Kennedy's Demise
    Video: YouTube

    On November 22, 1963, President John F. Kennedy was shot as he was riding in a presidential motorcade in Dallas, Texas. According to an investigation known as the Warren Commission, Kennedy was shot by sniper Lee Harvey Oswald, who acted alone (and was murdered by nightclub owner Jack Ruby days later). However, some believe that the Warren Commission was simply a means to cover up a conspiracy to kill Kennedy.

    Many allege that conflicting facts regarding the murder weapon, witness accounts and the autopsy of Kennedy suggest a coverup. Though few speculate as to the identity of the actual alleged killer, the CIA, KGB, Mafia, Federal Reserve, Fidel Castro, and sitting Vice President Lyndon B. Johnson were all mentioned as possibilities by various conspiracy theorists.

  • Moon Landing
    Video: YouTube

    Though many believe that NASA's Apollo 11 landed on the surface of the moon on July 20, 1969, many also believe that the famous "one small step for man, one giant leap for mankind" moment was faked. The moon landing hoax is one of the most well-known conspiracy theories with arguments continuing decades later about the event.

    Proponents of the hoax theory claim the United States faked the moon landing to win the space race and ultimately the Cold War with the Soviet Union. To do this, accusers claim the evidence of the astronauts on the moon was filmed in a sound stage in Hollywood based on a script created by Arthur C. Clarke and directed by Stanley Kubrick.

  • Area 51
    Video: YouTube

    Mentioned in the alien invasion movie Independence Day among others, Area 51 is a United States Military base that operates as part of Edwards Air Force Base in Nevada. Due to the intense security surrounding the remote installation, including that the US Government would not acknowledge the existence until 2003, many have speculated Area 51 is actually used to hide alien spacecraft that have crashed into the Earth.

    In July 1947, many claimed that an unusual object believed to be a UFO crashed in nearby Roswell, New Mexico. Conspiracists claim the Roswell incident is only one of several alien crash sites in the country with Area 51 used for alien autopsies.

    UPDATE: The existence of the covert Area 51 has been officially confirmed by the CIA in newly declassified documents obtained by George Washington University. The report documents the development of the secret U-2 spy plane, the history of how the covert area came into existence, and points to the precise location on an Atomic Energy Commission map.

    Because of the developmental plane's never-before-witnessed operating altitude and the way the silver wings would reflect the sun — seeming to be on fire — the UFO sightings started pouring in to air traffic controllers and the Air Force. The Air Force recorded the reports in their Operation BLUE BOOK, and investigators tried to calm concerned citizens by attributing the sightings to natural phenomena because they could not reveal the true, but classified, cause.