In the fiftieth year since the assassination of President John F. Kennedy, almost 150 more books were added to the thousands already written studying the man, his era and his death.

But the focus of academics and historians may be shifting, from an analysis of the events of that day, to the impact they have had on both the United States, and the world. 

Back in 1963, baby boomers were teenagers, yet even today, their memories of the American trauma are nearly as vivid as though it had just happened.

In Dealey Plaza, the site of the assassination in Dallas, a man looked out at the X painted in the middle of the street. With emotion in his voice he said, 鈥淪eeing it in person is an extraordinary experience鈥 mean it鈥檚 hard.鈥 

At a discussion in New York City people talked of the shock of that day and how the United States was changed by the assassination. And in Waterloo, Ontario, at yet another event to consider the impact of Kennedy鈥檚 early death on the world, Canadians recalled exactly where they were and what they were doing when they heard about the assassination.

My recollection is just as clear; walking home from high school and hearing the news as people passed me on Yonge Street talking about it. Then the weekend spent in front of the television. The shock when Jack Ruby shot Lee Harvey Oswald.

Fifty-one years later about a thousand Americans a day visit the site of the assassination. Some arrive clutching old photos taken by family members who happened to be in the plaza on that day.  The younger relatives wander around trying to find the exact spot where their mother, or father, aunt or uncle stood the moment the bullets struck.    

And then there are those that who dodge traffic, dashing out into the busy road to stand on the x painted onto the asphalt, marking the exact spot where the fatal bullet struck.  They pose for a quick photo. You can the scene live repeated time and again. For years the city of Dallas did little to mark the assassination. At one time the Book Depository, from where Oswald fired the shots, was up for demolition. In the end the building was saved and the sixth floor with the famous corner window behind which the assassin perched, has been preserved exactly as it was, the most important exhibit of a that now houses a collection of 40,000 items.

Hugh Aynesworth was a local reporter without an assignment that day so he walked over to watch the motorcade. Standing on the corner across from the Book Depository he heard the shots.  He would spend much of the rest of his long career studying and writing about the event.  He remembers in the initial confusion, seeing an eyewitness point up at the 6th floor of the depository building. 

Robert MacNeil was a Canadian journalist then working for NBC News. Kennedy鈥檚 trip to Dallas was MacNeil鈥檚 first covering the president outside Washington. MacNeil broke the story live on NBC News that afternoon. As MacNeil ran into the Book Depository looking for a phone he thinks he might have run past Lee Harvey Oswald leaving.

While the assassination is seared in the memories of a generation the question many ask is what if Kennedy had lived?

Kennedy became President at the height of the Cold War. The United States and the Soviet Union were engaged in an all-out arms race and the threat of nuclear war was a daily reality. The two sides faced each other in Southeast Asia, Berlin and Cuba, and on at least two occasions, came close to a nuclear holocaust.     

Jim Blight, is the Chair of Foreign Policy Development at the Balsillie School of International Affairs in Waterloo, Ontario. He has put together a project called . Blight believes that Kennedy and the Soviet leader Nikita Khruschev were on the verge of making dramatic steps to making the world a safer place.  He believes if Kennedy had lived, he would have worked with Khrushchev to initiate a thaw in the cold war, and with it, a reduction in the world鈥檚 nuclear arsenals. He concludes that the assassination is 鈥渙ne of the great tragedies of the 20th 颁别苍迟耻谤测.鈥

Blight also says the evidence now available suggests Kennedy would not have dragged his country into that disastrous conflict in Vietnam that eventually cost the lives of nearly 60 thousand Americans and millions of Vietnamese.  Blight says Kennedy, 鈥渨as not going to war in an era where war could escalate to nuclear catastrophe.鈥

That opinion is shared by Jeff Greenfield the American political commentator and author of If Kennedy Lived. Greenfield points out that without the Vietnam war the United States in the 1960s would have been very different. 鈥淵ou would not have had the level of anti-Americanism鈥he embrace of flag burning and revolutionary rhetoric.鈥

Considering 鈥榳hat might have been鈥 both Greenfield and Blight say Kennedy always approached a crisis wanting to know the worst case scenario. Greenfield says Kennedy鈥檚 鈥渄riving concern was miscalculation and lack of information.鈥 Blight adds that Kennedy always asked, 鈥淲hat is the worst thing that can happen here?鈥

Kennedy came to the presidency as a young, charismatic leader promising hope and change.  It all ended in the six seconds it took an assassin to kill him.  After fifty years of study, most historians are confident they know every detail of how he died.  What they鈥檙e trying to understand now is: what if he鈥檇 lived?