A heartbreaking moment in history, at 12:30 p.m. on this day in 1963, President John F. Kennedy was shot to death by Lee Harvey Oswald from the sixth floor corner window of the former Texas School Book Depository in Dallas.

We've seen the graphic Zapruder film of the Dealey Plaza drama: The motorcade riding the center lane on Elm Street, passing the grassy knoll, sloping toward the Triple Underpass, heading for the Trade Mart where the President was scheduled to praise the city's "forward-looking Graduate Research Center of the Southwest."

Kennedy never made it there. Instead, the world was left with grief, grainy photographs, documentaries, investigations, what-ifs, and theories. JFK's assassination became a defining moment. In 40 years, the mystique remains.

Kennedy once said, "We have the capacity to make this the best generation in the history of mankind, or make it the last."

The legeacy of Kennedy's brief life? His leadership inspired a passion for achievement and a promise for the future. "A Pulitzer Prize winner with subtle mind and a passion for cutting through cliches," praised biographer William Manchester.

Each year, an estimated 2.2 million people visit Dealey Plaza Park, the 3.07-acre gateway to the city's beautiful downtown metroploitan area, the place where time stood still. In 1993, the plaza was designated a National Historic Landmark District to remember and honor, with the seed of history's own lesson.

More JOHN KENNEDY Quotations

With heartbreak comes healing.