JFK: His ambition and legacy

President John F. Kennedy greets the crowd in Fort Worth, Texas, November 22, 1963, just hours before he was felled by an assassin's bullet in Dallas.
Cecil Stoughton/John F. Kennedy Presidential Library and Museum

(CBS News) Ask anyone above a certain age and they can tell you exactly where they were when they heard the news of John F. Kennedy's death. It was an incomprehensible end to a presidency that had begun on such a thrilling and inspiring note. Our Cover Story is reported by Rita Braver:

"Let every nation know, whether it wishes us well or ill, that we shall pay any price, bear any burden, meet any hardship, support any friend, oppose any foe, in order to assure the survival and success of liberty."

He was the youngest-elected president in history, coming into office at the height of the Cold War -- a man endowed with grace, good looks, and a wide-ranging intellect.

"He had a gift for touching the best, humane, most idealistic impulses in America," said historian Robert Caro. "He had a gift for rallying the country."

And 50 years after his death, Americans are still fascinated by him.

So we asked Caro and two other noted historians to help us explore John Fitzgerald Kennedy's life and his presidency.

Robert Dallek believes at least that part of the attraction is that Kennedy died so young.

"He's frozen in our minds at the age of 46," he said. "People can't imagine that if he were alive today, he'd be 96 years old. So there he is, so youthful, so handsome, so charming, so witty."

Thurston Clarke said Kennedy was also a very complicated human being: "John F. Kennedy is a marvelous human puzzle. You think you have gotten to the end of it, you think you've solved it, and then something else happens."

He was born in 1917, the second of nine children, into a legendary Irish-American family. His father, Joseph, was a multimillionaire who served as ambassador to Great Britain.

In 1941, after graduating from Harvard, John Kennedy enlisted in the Navy.

As World War II raged on, he took command of PT 109, a small torpedo boat that was ultimately cut in half by a Japanese destroyer in the South Pacific.

"He takes one of the men, who is severely injured, burned, takes his life belt and puts it between his teeth," said Dallek, "and swims something like half a mile to a nearby island, dragging this man along with him."

Kennedy is hailed as a hero. But it was only after his older brother Joe, a Naval aviator, was killed in action, that John Kennedy decided on a political career, serving in the House and then Senate.

"It wasn't his father entirely tapping him on the shoulder [saying], 'Boy, you're next,'" said Clarke. "This is a very ambitious man. I think if you rated presidents on ambition, I think Kennedy would be at the top of the list."

And that ambition led Kennedy to run for the White House in 1960, despite what was considered a lackluster Congressional career.

Braver asked, "What gives this man the kind of chutzpah to say, 'I'm going to be president'?"

"For one thing, there's a genius about him," replied Caro. "He can see trends. He can generalize from what he's watching. And he knows that he's great on television. He knows there's a new force coming in politics in America, and it's television."