In October 1957 at the dedication of a gymnasium in memory of another Kennedy sister Kathleen Cavendish, Marchioness of Hartington — who had died in a plane crash in 1948 — Jean Kennedy introduced Joan to her brother Ted Kennedy, then a student at the University of Virginia School of Law.
They were married on November 29, 1958, in Bronxville, New York. Her brother-in-law, John F. Kennedy, dubbed her "the dish", because of her good looks and fashionable style.
They had three children: Kara Anne (née Kennedy) Allen (born February 27, 1960, in Bronxville), Edward Moore Kennedy, Jr. (born September 26, 1961), and Patrick Joseph Kennedy (born July 14, 1967).
Two of their children would later develop cancer. Edward Jr. developed bone cancer that resulted in the removal of a portion of a leg in 1973 and Kara was treated for lung cancer in 2003.
After her husband suffered a severe back injury in an airplane crash while campaigning, she assumed the full campaign-appearance schedule for election to his first full term in the U.S. Senate 1964 election. He had won a special election in November 1962 to serve the final two years of his brother, President John F. Kennedy's senate term.
In July 1969, her husband was involved in a car accident off Chappaquiddick Island in Massachusetts that killed his passenger, Mary Jo Kopechne. Although pregnant and confined to bed in the wake of two previous miscarriages, she attended the Kopechne's funeral. Three days later, she stood beside her husband in court when he pled guilty to having left the scene of an accident. She suffered a third miscarriage shortly thereafter.
In early 1978, the couple separated. Shortly thereafter, she gave interviews with People and McCall's confirming her alcoholism and her work to stay sober.
The couple remained together during his failed 1980 U.S. presidential campaign, announcing plans to divorce in 1981. The divorce was finalized in 1982, one year to the day after filing for divorce.