Janet and Black Jack had a troubled marriage and they separated in 1936. They reconciled briefly in 1937 but were divorced in 1940. Jackie lived with her mother, though she did see her beloved father frequently. In 1942 Janet married Hugh Dubley Auchincloss, Jr., who was a lawyer from a prestigious old family. The Auchinclosses were much wealthier than the Bouviers, and Jackie and Lee lived with their mother and her new husband. The Auchinclosses had two more children, Janet, Jr., who was born in 1945, and Jamie, who was born in 1947. The mother's remarriage created a rift in the family. Though Jackie adored her father, she saw less and less of him, particularly since her mother and stepfather moved their family to Washington, D.C. The summers were spent at the Auchincloss home, Hammersmith Farm, in Newport, Rhode Island. In 1944 Jackie was sent to boarding school at Miss Porter's in Farmington, Connecticut.

Jackie was a beautiful and elegant young woman, and when she made her social debut the Hearst newspaper gossip columnist named her Debutante of 1947. Jackie went on to college at Vassar, where she seemed embarrassed by the notoriety attached to her social success. She was a serious student who worked hard and made the dean's list. She spent her junior year abroad in Paris, which she loved.

Jackie returned to the United States and finished college at George Washington University in Washington, D.C. She entered a writing contest sponsored by Vogue magazine called the "Prix de Paris," which she won. The winner was to receive a year-long position as a trainee at Vogue, spending six months in their New York office and six months in the Paris office. Jackie's parents, especially her stepfather, felt that she had spent a long time in Europe already, and they were concerned that if she took the job she would not return to the United States. At their request Jackie turned down the offer and went to work instead at the Washington Times-Herald newspaper as a photographer.

In 1951 Jackie met John Fitzgerald Kennedy for the first time. The next year Kennedy was elected senator from Massachusetts and moved to Washington. The two continued to see each other and became engaged in June 1953. On September 12, 1953, Jacqueline Lee Bouvier married John Fitzgerald Kennedy at an enormous wedding that was the social event of the season. There were 1,300 guests at the reception. The only event that marred the wedding for the bride was the fact that her father, who had become an alcoholic, did not attend the wedding.

Jackie Kennedy was a shy, private woman with little experience in politics or knowledge of politicians, but she was a help to her husband in many ways. She worked with him on his public speaking, helping to develop the charismatic style for which he would become so famous. In 1954 Kennedy had surgery to try to alleviate the constant pain he suffered from a back injury. Jackie spent the recovery period by his side.

In 1956 there was speculation that John Kennedy would be the Democratic vice presidential nominee. Many members of the Kennedy family attended the convention, which was an exciting and exhausting one. Jackie was there to lend her support, despite the fact that she was seven months pregnant. Though Jack Kennedy gave a speech nominating Adlai Stevenson as the Democratic candidate for president, Estes Kefauver was selected as the vice presidential candidate.

On August 23, soon after her husband had left for a short vacation, Jackie went into premature labor. The baby was stillborn, and it was Jackie's brother-in-law Bobby Kennedy who consoled her and made the arrangements for the baby's burial.

In 1957 Jackie suffered another loss when her father died. This was also a difficult period in the Kennedy marriage. Much was rumoured at the time and has been written subsequently about the various extramarital affairs that John Kennedy had both before and during his presidency, all of which undoubtedly put a strain on their marriage.

On November 27, 1957, Caroline Bouvier Kennedy was born. Just months after Caroline's birth her father was up for reelection as senator from Massachusetts, and Jackie was active in the 1958 senatorial campaign as well.

Soon after Kennedy was returned to Washington by his constituents he began to seek the presidential nomination. Jackie campaigned vigorously for her husband until she became pregnant for the third time. She continued to help as much as she was physically able until the birth of their son, John Jr., on November 25, 1960.

As soon as John Kennedy was elected president, Jackie began working to reorganize the White House so that she could turn it into a home for her children and protect their privacy. At the same time she was well aware of the importance of the White House as a public institution. She formed the White House Historical Association to help her with the task of redecorating the building. She also formed a Special Committee for White House Paintings to further advise her. While as a mother Jackie was interested in protecting her children, as First Lady she felt strongly that the White House was a national monument. She wrote the forward to The White House: A Historical Guide. She also developed the idea of a filmed tour of the White House that she would conduct. The tour was broadcast on Valentine's Day 1962 and was eventually distributed to 106 countries.

In April 1963 the Kennedys announced that Jackie was pregnant. On August 7, 1963, Patrick Bouvier Kennedy was born. He died three days later.

In November of 1963 Jackie Kennedy accompanied her husband on a trip to Texas. She was riding by his side when an assassin’s bullet struck John Kennedy, killing him instantly. Lee Harvey Oswald was immediately pinned as the rifleman. Two days later, as police escorted Oswald from a county jail, he was shot and killed by Dallas nightclub owner Jack Ruby. To this day, there has remained an undercurrent of suspicion about the role of the FBI in covering up evidence surrounding Kennedy’s death, and Oswald himself claimed to be nothing more than “a patsy” in the murder, leading to further speculations about a conspiracy theory. In the days that followed his death the image of his widow and children, and the dignity with which they conducted themselves, were very much a part of the nation's experience of mourning and loss.

In the years immediately after her husband's death Jackie Kennedy was seen very much in the role of his widow, while at the same time there was constant speculation about whether or not she would remarry. Jackie was actively involved in Bobby Kennedy's presidential bid in 1968, however, tragedy struck again in June when Bobby was assasinated by Sirhan Sirhan, a Jordanian immigrant, immediately after winning the California Democratic presidential primary.

In October 1968, Jackie Kennedy married Aristotle Onassis, a Greek shipping magnate. He was 62 and she was 39. Jackie spent large portions of her time in New York to be with her children. As the years went by, the Onassis marriage was rumored to be a difficult one, and the couple began to spend most of their time apart. Aristotle Onassis died in 1975 and, widowed for a second time, Jackie returned permanently to New York.

In 1975 she began working as a book editor at Viking amidst much speculation about whether or not she would be able to get along with her fellow workers, or if her very presence would make it difficult for the office to function. She quickly adapted to her new job and remained at Viking until she resigned in 1977. In 1978 she took a job as an associate editor at Doubleday Publishing where she continued to work into the 1990s. In 1982 she was promoted to full editor and later became a senior editor.

In 1994 Jackie Kennedy made public the information that she was being treated for non-Hodgkin's lymphoma and that her condition was responding well to therapy. However, the disease proved fatal on May 19, 1994. She is buried next to John F. Kennedy in Arlington National Cemetery.

Her daughter Caroline is a mother and lawyer. Her son John was the editor in chief of the political magazine George until his death in a plane crash in 1999. John Jr.'s wife, Caroline Bessette-Kennedy, and her sister, Lauren Bessette, also perished in the crash.