"Now in the sunny freshness of a Texas morning," LIFE magazine wrote in its Nov. 29, 1963, issue, alongside the first photo in this gallery, "with roses in her arms and a luminous smile on her lips, Jacqueline Kennedy still had one hour to share the buoyant surge of life with the man at her side."
It was a wonderful hour [LIFE wrote, just a week after JFK's assassination]. Vibrant with confidence, crinkle-eyed with an all-embracing smile, John F. Kennedy swept his wife with him into the exuberance of the throng at Dallas' Love Field. This was an act in which Jack Kennedy was superbly human. Responding to the warmth his on genuine warmth evoked in others, he met his welcomers joyously, hand to hand and heart to heart. For him this was all fun as well as politics. For is shy wife, surmounting the grief of her infant son's recent death, this mingling demanded a grace and gallantry she would soon need again.
Then the cavalcade, fragrantly laden with roses for everyone, started into town. Eight miles on the way, in a sixth-floor window, the assassin waited. All the roses, like those abandoned in Vice President Johnson' car [last slide in this gallery], were left to wilt. They would be long faded before a stunned nation would fully comprehend its sorrow.
Here, on the anniversary of JFK's assassination, LIFE.com presents photos by Art Rickerby — most of which never ran in LIFE — made in the hours before, as well as the moments immediately after, the killing that shocked the world.