How Jackie Kennedy Spent the Anniversary of JFK's Death Over the Years (Exclusive)

The afternoon of Nov. 22, 1963, shaped the future of America for all of its citizens, none more so than Jacqueline Kennedy.

In one moment, she was the first lady of the United States, riding through Dealey Plaza on a sunny, cheerful day in Dallas, Texas. In the next, she was cradling the lifeless body of her husband, John F. Kennedy, and mourning the loss of her entire life for hundreds of cameras to capture.

It's impossible to forget the image once you've seen it. The shell-shocked first lady, in her double-breasted, raspberry pink Chanel suit and matching pillbox hat, soaked in her husband's blood. For Jackie, of course, the tragedy haunted her for the rest of her life.

"She regretted that she was never able to get over it," Kennedy historian J. Randy Taraborrelli tells PEOPLE. "At the end of her life, she regretted that she had let herself be defined by it.”

Born Jacqueline Lee Bouvier, the future first lady was just 23 when she met John Fitzgerald Kennedy at a dinner party in 1952. He was already running for a U.S. Senate seat in Massachusetts, so a relationship meant linking herself to the fastest-rising star from one of the country's most powerful families. By the next year, they'd be married; in less than a decade, they'd be living in the White House.

It's perhaps not surprising, then, that Jackie felt her life was overshadowed by JFK's death, even when she lived for more than 30 years after that tragic day in Dallas.

In his biography, Jackie: Public, Private, Secret, Taraborrelli recounts a conversation Jackie had with architect Jack Warnecke, her longtime friend and, briefly, her lover, towards the end of her life.

“I got past it, maybe, but never over it," she said of the assassination. “What a shame, to spend so much time tormented by a thing I could never change.”

In the years that followed her husband's death, Jackie did her best to isolate herself from the news. The anniversary was marked not just by the day itself, but by the media hubbub, memorials and tributes that surrounded it.

“She stopped all the papers for those two weeks: the week before and the week after,” Taraborrelli says, noting that a headline or tribute could trigger a fresh wave of grief, no matter how many years had passed.

With each year that passed, Jackie perhaps never grieved less, but she did grieve differently. For the first anniversary of the assassination, she penned a tribute to her late husband for Look magazine, which made it evident how deeply sunk in her grief she still was.

“What was lost cannot be replaced," Jackie wrote. "I should have guessed that it could not last.… I should have known that it was asking too much to dream that I might have grown old with him and see our children grow up together."

"So, now, he is a legend when he would have preferred to be a man," she continued. "I must believe that he does not share our suffering now. I think for him—at least he will never know whatever sadness might have lain ahead.. not age, not stagnation, nor despair, nor crippling illness, nor loss of any more people he loved.”

As the years passed, Jackie's children, Caroline and John Jr. — who were just 5 and 2 years old, respectively, when their father died — became her protectors in grief. Especially young John, who knew what to keep out of his mother's eyesight when the anniversary was drawing near.

As Taraborrelli recounts, "Whenever an article or a book came out that showed the motorcade in Dallas or the blood-stained dress, he would take the book or magazine from his mother and say, 'I don't want you to see that.' "

"He was so protective of his mom. He didn't want her to relive those moments all these years later," the biographer notes.

Another protective moment came one year on the anniversary, when Jackie was walking young John home from school, and a classmate began chanting taunts about his dead father.

“That was so traumatic for Jackie,” Taraborrelli says. “But John just said, ‘Oh, don’t worry about him.’ "

The 10th anniversary of JFK's death was especially harrowing for the former first lady. By then, the family had suffered yet another devastating loss, when JFK's younger brother, Robert F. Kennedy, was also gunned down by an assassin as he kicked off his presidential campaign in 1968.

In 1973, RFK's widow, Ethel Kennedy, hosted a memorial Mass at her home, Hickory Hill, in McLean, Va. Jackie, Caroline and John Jr. all attended; however, being away from home meant there was no one to keep the papers out of Jackie's eyesight.

"There was a copy of Ladies' Home Journal on the counter," Taraborrelli recounts. "On the cover was an interview with Marilyn Monroe's nurse" — traumatizing to Jackie for reasons unrelated to the assassination — "and the new installment of Jim Bishop’s book, The Day Kennedy Was Shot."

“Both of them [Jackie and Ethel] just burst into tears,” the biographer shares.

Taraborelli interviewed Ethel's personal assistant, Noelle Bombardier, for Jackie: Public, Private, Secret, and recounts an anecdote that she shared that's always stuck with him.

Bombardier recalled Jackie asking her, later in the emotional day, “Do you think Ethel will ever get over what happened to Bobby?”

When asked why, the former first lady admitted, "I keep thinking maybe if she does, so will I."

As her children grew older, Jackie hoped to keep them connected to the memory of their father, removed from the legend of JFK that exists in American history books. Taraborrelli recounts interviewing JFK Jr. in support of the launch of his George magazine in 1995. He asked the late president's namesake son if he remembered moments with his father that had become famous to the public — like the shots of father and son playing in the Oval Office.

“I don’t know,” John Jr. admitted. “I don’t know if I actually remember or I just remember because I’ve seen the pictures.”

One way Jackie strived to "keep John alive for the kids," Taraborrelli says, was through their faith. On major anniversaries of JFK's death — like the 30th, in 1993, just a few years before JFK Jr. would meet his own tragic end — they would attend a requiem mass at St. Thomas More, a small Catholic church on the Upper East Side.

The nuclear family grieved privately at each milestone, joined, in time, by new members of the family, like Caroline's husband, Edwin Schlossberg, and their three children.

Jackie only returned to the White House once following her husband's death.

JFK's successor, President Lyndon B. Johnson and his first lady, Lady Bird, were nearly "desperate" to have her back, Taraborrelli says, as "a sort of endorsement" of their new administration, but she couldn't bring herself to return.

It wasn't until 1971 that she caved, accepting an invitation from then-first lady Pat Nixon, on the occasion of the unveiling of her and President Kennedy's official portraits.

It wasn't the pomp and circumstance that enticed Jackie back, Taraborrelli notes, sharing, "She wanted Caroline and John to see the Oval Office." The children were 14 and 11 by then, a better age to appreciate the importance of their father's time as president.

However, Taraborelli says Jackie insisted on one stipulation for the visit: no cameras, no press, no public announcement of any kind.

“It's a shame,” the biographer laments of the missed opportunity to see the Kennedys in the White House once again. “But the Nixons honored her wishes.”

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer​​, from celebrity news to compelling human interest stories.

In his Jackie book, Taraborrelli shares the touching text of the note Jackie wrote to Pat Nixon the following day.

“Can you imagine the gift you gave me? To return to the White House privately with my little ones while they are still young enough to rediscover their childhood—with you both as guides?” she said.

“Your kindness made real memories of his shadowy ones,” she continued. “Thank you with all my heart. A day I dreaded turned out to be one of the most precious ones I have spent with my children.”

J. Randy Taraborelli's latest Kennedy biography, JFK: Public, Private, Secret, is out now in hardcover and available to pre-order in paperback.