From a sixth-floor corner window of the Texas School Book Depository, Lee Harvey Oswald, a 24-year-old former Marine who had defected to the Soviet Union and returned, fired three rounds from a 6.5mm Mannlicher-Carcano rifle. One bullet struck Kennedy in the upper back, exited through his throat, and -- according to the Warren Commission -- continued through Governor Connally's shoulder, wrist, and thigh. A second bullet hit the president in the back of the head. The Secret Service driver accelerated toward Parkland Memorial Hospital, four miles away. Jacqueline Kennedy, still in her pink Chanel suit now spattered with blood, cradled her husband. At 1:00 p.m., thirty minutes after the shooting, Kennedy was pronounced dead. CBS anchor Walter Cronkite broke the news to the nation on live television, pausing to remove his glasses and steady himself.

What followed compressed a lifetime of national trauma into a single afternoon. Oswald slipped out of the Book Depository and took a bus to his boarding house, where he retrieved a jacket and a revolver. At 1:12 p.m., Dallas police officer J. D. Tippit spotted Oswald in the Oak Cliff neighborhood and called him over. After a brief exchange, Oswald shot Tippit four times and walked away. At 1:36 p.m., he was seen sneaking into the Texas Theatre without paying. Police arrested him during the movie 'War Is Hell' after a struggle in which Oswald drew a loaded gun. He told reporters he was a 'patsy.' Meanwhile, Lyndon Johnson refused to leave Dallas without Jacqueline Kennedy, and she refused to leave without her husband's body. A heated argument between Kennedy's aides and Dallas officials nearly turned physical before the Texans relented. At 2:38 p.m., aboard Air Force One with Jacqueline still in her bloodstained suit at his side, Johnson took the oath of office from federal judge Sarah Tilghman Hughes.

Two days later, on the morning of November 24, as Oswald was being transferred to the county jail, Dallas nightclub owner Jack Ruby stepped from a crowd in the basement of police headquarters and shot him once in the abdomen. The killing was broadcast live on national television -- the first murder most Americans had ever witnessed in real time. Oswald was rushed to Parkland Memorial Hospital, where the same surgeons who had tried to save Kennedy worked to save his assassin. He died at 1:07 p.m. Ruby claimed he acted to spare Jacqueline Kennedy the ordeal of a trial. He was convicted but won an appeal; while awaiting retrial in 1967, Ruby died of a pulmonary embolism from lung cancer. Like Kennedy and Oswald before him, Ruby was pronounced dead at Parkland Hospital.

Today the Texas School Book Depository houses the Sixth Floor Museum, which opened in 1989 on the floor from which Oswald fired. The corner window where he positioned his rifle is reconstructed with period boxes. Below, Dealey Plaza itself is a National Historic Landmark, its contours essentially unchanged from that November afternoon. A white X on Elm Street, painted and repainted by unknown hands whenever the city removes it, marks the approximate spot where the fatal shot struck. The grassy knoll, the pergola, the triple underpass -- these features of a small Dallas park have become permanent fixtures of the American imagination. A quarter million people passed through the Capitol rotunda during the eighteen hours Kennedy lay in state. An eternal flame was lit at his grave in Arlington. More than sixty years later, a majority of Americans still believe Oswald did not act alone.