Of course 9/11 was a conspiracy in that it was an organized terrorist attack; however, the nutjobs there aren't talking about that but instead try to pin it on the Bush administration being actively involved.
The question of whether Oswald acted alone has produced reams of books that get longer and more convoluted by the year, bent on proving that the Warren Commission was incorrect in its assessment of Oswald as the lone conspirator. Whether it was the bizarre counter-assassination by Jack Ruby or Frame 313 in the Abraham Zapruder film footage of the actual assassination, evidence suggests that Oswald was part of perhaps the greatest American political conspiracy, these authors say.
The Kennedy assassination, however, has no small amount of competition when it comes to American conspiracy theories. In the 18th century, Roman Catholics were rumored to be setting up a shadow government west of the Alleghenies to destroy US liberties. Slave conspiracy paranoia "was one of the most significant cultural phenomena of pre-Civil War America," according to "Conspiracy Theories in American History: An Encyclopedia." And, of course, Sen. Joseph McCarthy was convinced that Communists were corrupting the nation in the 1950s.
A lot of this nonsense is a direct result of the distrust in government that was in large part brought about because of the assassinations and general social upheaval of the 1960s and early 1970s. Watergate was the end of that era of upheaval and really was a conspiracy, but the end result was mistrust of government running rampant.
Getting back to the JFK assassination, it really is LONG overdue to put the idiotic conspiracy theories to rest. They get stupider and stupider with time:
Records show that Oswald was the buyer and owner of the rifle used to kill Kennedy. No other weapon has been found that can be linked to the assassination.
No bullet other than those from Oswald’s rifle has ever been recovered and linked to the assassination.
Oswald was the only Texas School Book Depository employee who turned up missing after the assassination.
Forty-five minutes after Kennedy was shot, Oswald shot and killed Dallas police officer J.D. Tippit with a .38-caliber revolver at the intersection of 10th Street and Patton Avenue in Oak Cliff.
Minutes after Tippit was shot, Oswald pulled the same revolver on a Dallas police officer attempting to arrest him at the Texas Theatre on Jefferson Boulevard in Oak Cliff.
The Warren Commission in 1964 and the House Select Committee on Assassinations in the late 1970s spent a combined four years investigating JFK’s murder and never found evidence linking the CIA, the Mafia, anti-Castro Cubans or any other group to the crime. Investigators conducted 25,000 interviews and never linked Oswald to any of those suspect groups.
The truth doesn't stop the nutjobs as long as there is money to make peddling whatever crazy theory about 11/22/63.