Patricia Kennedy Lawford, a sister of President John F. Kennedy whose wedding to actor Peter Lawford in the 1950s was one of the first marriages of politics and Hollywood and provided her brother with many of his closest entertainment industry ties, has died. She was 82.

Lawford died Sunday at her home in New York City of complications from pneumonia, according to a statement from the Kennedy family.

"My sister Pat is irreplaceable," Sen. Edward M. Kennedy (D-Mass.) said in the statement. "Everyone who knew Pat adored her. She was admired for her great style, for her love and support of the arts, her wit and generosity -- and for the singular sense of wonder and joy she brought into our lives.

"Throughout her life, Pat was constantly inspiring and helping others. Whether it was campaigning for her brothers or championing literacy and the arts, her purest gift was her beautiful heart, and it shone brightly in all she did."

While living in New York, Pat Lawford became a founder of the National Committee for the Literary Arts, which provided a series of author lectures and scholarships. She was involved with the refurbishment of the exhibits at the John F. Kennedy Library and Museum in Boston. She also served as an officer of the Kennedy Foundation for the Mentally Retarded.

In 1964, she served as the statewide co-chairperson of former Kennedy White House press secretary Pierre Salinger's campaign for the U.S. Senate from California, and she campaigned the same year for California Democratic congressional candidate John V. Tunney, who later was elected U.S. senator. She also supported the various campaigns of her brothers, President Kennedy, U.S. Sen. Robert F. Kennedy (D-N.Y.) and Ted Kennedy.

Biographer Laurence Leamer, who interviewed Lawford for his 1994 bestselling book "The Kennedy Women," said in a 2003 interview that Lawford "was known for being a very genteel soul and a good friend."

"As her older sister Eunice seemed to have been born with a sense of humanity, so Patricia appeared to have been blessed from birth with a natural grace and bearing," Leamer wrote in his book.

In the words of Nobel Prize-winning writer and social activist Pearl S. Buck, Pat Lawford was "the most attractive, the least dominating, the most yielding and gentle" of the Kennedy girls.

Growing up, Pat Kennedy didn't participate in the family's fabled competitiveness as much as her siblings, according to Leamer, who wrote: "She was a graceful creature on the tennis court, or sailing a boat with great natural ability, but she didn't care if she won or lost, not the way Eunice, Jack and Joe Jr. cared."

The sixth of Joseph and Rose Kennedy's nine children -- four boys and five girls -- Patricia was born May 6, 1924, in Brookline, Mass., a wealthy suburb of Boston.

During Joseph P. Kennedy's stint as U.S. ambassador to Britain from 1937 to 1940, Lawford and sisters Eunice and Jean attended the Sacred Heart convent, an exclusive boarding school on the outskirts of London.

After the family returned to the United States, she studied at Maplehurst, a Sacred Heart school on a former estate on the fringes of the Bronx and only 15 minutes from home in a chauffeur-driven car from the Kennedy mansion in Bronxville, N.Y.

As a teenager, Leamer wrote, "Pat was a tall, lanky, sweetly tempered young woman of striking good looks bound to have her full share of male admirers."

She attended Rosemont College, a small Catholic women's school in Rosemont, Pa., where she became the school tennis champion and graduated in 1945.

Leamer told The Times that Pat Kennedy had "the best athletic potential" of all the Kennedys. "She was a terrific golfer," he said. "Some think she could have been a professional women's golfer; that's how good she was."

In 1949, she moved to Los Angeles, where she worked as a production assistant on singer Kate Smith's radio program. She later was a producer on Father Patrick Peyton's "Family Rosary Crusade," which coined the household phrase, "The family that prays together stays together."

As a member of one of America's wealthiest families, Pat Kennedy didn't need to work. Thanks to trust funds Joe Kennedy had established for his children, she reportedly had a personal fortune of $10 million by her 30th birthday.

During John Kennedy's 1946 run for Congress, she joined her sisters to work in their brother's campaign office during the day and accompany him to meet-the-candidate house parties in the evening.

She was living in Manhattan in November 1953 when she ran into Peter Lawford, a British-born actor whom she had met several times before. Although the debonair Lawford had been one of Pat Kennedy's favorite film stars in the 1940s -- someone she deemed "divine" at the time -- nothing had come of their previous encounters.

But this time they began seeing each other; after only two months, they were engaged.

"Pat's a tremendous person," Lawford once said. "She has a terrific mind. A great sense of loyalty. She's so honest. There's no pretense about her at all. And she has such a wonderful outlook on everything."

New York society columnist Cholly Knickerbocker hailed the Kennedy-Lawford engagement, which was cemented with an eight-carat diamond ring, as "one of the great romances of the year." Some 250 friends and relatives attended their wedding in the small Roman Catholic Church of St. Thomas More on Manhattan's Upper East Side in April 1954. The bride had planned on a quiet wedding, but it proved to be anything but.

A crowd of several thousand people gathered outside the church, requiring the presence of 20 policemen, who cordoned off the entire block. Most of the people in the crowd were what the press described as "squealing bobby-soxers" who wanted to catch a glimpse of the dashing Lawford.

When the newlyweds emerged from the church, the crowd erupted in cheers and cried out Lawford's name.

"Isn't he \o7gorgeous," \f7one girl shrieked as the crowd surged around the couple.

The horde of fans knocked the bride's cap and veil askew as the newlyweds made their way to a waiting limousine, and fans ran after the limo as it carried the couple to their reception at the Plaza Hotel.

The Lawfords later bought a beachfront mansion in Santa Monica that had once been owned by Louis B. Mayer and which became a hideaway for John Kennedy.

"Whenever Kennedy would come to Los Angeles, he'd be entertained there," Leamer said.

When President Kennedy was assassinated in Dallas on Nov. 22, 1963, a psychiatrist, nurses, neighbors, friends and the pastor of St. Monica's Church in Santa Monica descended on the Lawfords' home to comfort Pat Lawford.

The next day, a grief-stricken Lawford, her husband and their 7-year-old daughter, Sydney, flew to Washington, D.C.

At the time of John Kennedy's assassination, Leamer said, the Lawfords' marriage was already "falling apart, and she had problems with that. Then her brother dies and in some ways she never really came back from that."

The Lawfords were divorced in 1966, the first divorce by a member of the Roman Catholic Kennedy family. Pat Lawford was granted custody of their four children, Christopher, Sydney, Victoria and Robin.

The couple had separated more than a year earlier, when Pat and the children moved to a Manhattan apartment and Peter Lawford remained in Santa Monica.

Pat Lawford never remarried; Peter Lawford died in 1984.

Although Pat Lawford was considered to be the least comfortable of the three Kennedy sisters on the political platform, she had a strong sense of familial duty and was always available when needed.

That was illustrated in Leamer's book in an incident that also clearly demonstrated that she shared the fabled Kennedy wit.

During Ted Kennedy's 1980 presidential campaign, an agitated campaign worker called Lawford, saying a Kennedy family member had been promised at a political gathering "and we have nobody." What's more, the campaign worker said, the meeting is in an hour.

"In an hour!" Lawford exclaimed. "Why my hair is a fright. I don't have any makeup on. I've got this old dress. I look like a total wreck. Why, it's impossible."

"But, Mrs. Lawford, what are we going to do?" implored the frantic campaign worker.

"All right, then," Lawford said. "I'll come as Eunice."

Lawford's brother, Robert, was killed by Sirhan Sirhan at the Ambassador Hotel in Los Angeles in 1968. Her oldest brother, Joseph Jr., died while flying a fighter plane in World War II, and a sister, Kathleen, died in a plane crash in France in 1948. Rosemary Kennedy, another sister, died in 2005.

Lawford is survived by four children and 10 grandchildren; her brother, Ted; and sisters Eunice Kennedy Shriver and Jean Kennedy Smith.

Services are pending.

Patricia K Lawford