WHITE PLAINS, N.Y. >> Kerry Kennedy was swiftly acquitted Friday of drugged driving in a case that her lawyers said would never have been brought if she were simply “Mary Housewife” rather than a member of one of America’s most glamorous political families.

After four days of testimony, a six-person jury took a little over an hour to find Kennedy not guilty of driving while impaired. She was arrested in 2012 after swerving into a tractor-trailer on an interstate highway in her Lexus.

The 54-year-old human-rights advocate — the daughter of Robert F. Kennedy, niece of President John F. Kennedy and ex-wife of New York Gov. Andrew Cuomo — testified she mistakenly took a sleeping pill instead of her daily thyroid medication the morning of the wreck.

If convicted, she could have been sentenced to a year in jail, though that would have been unlikely for a first-time offender.

Her lawyers made sure that the jurors knew all about her famous family. But after the acquittal, they said she should have been treated like “Mary Housewife.” And they accused prosecutors of giving her special treatment by refusing to drop the case.

The district attorney’s office denied the accusation. And Kennedy herself said she wasn’t angry about being put on trial.

In a show of the Kennedy clan’s famous loyalty, the defendant’s 85-year-old mother, Ethel Kennedy, attended the trial daily. Nearly a dozen other members of the family came by, including three brothers, two sisters, a sister-in-law and three daughters.

Laurence Leamer, who has written three books about the Kennedys, said: “The Kennedys are very loyal to each other in a crisis. … It’s one of the most admirable things about them.” He said there’s no way to gauge the effect on the jury, but “Kennedys or not, it’s Defense 101 to have family members sitting there for the jury to see.”

Tobe Berkovitz, a political media consultant and professor of advertising at Boston University, said: “The Kennedys saw this as a DA overreaching, making a big case out of a silly mistake. So they absolutely played every Camelot trump card they had in the deck. They had the family. They had questions about her losing her father as a young girl.”

He added, “When the legacy is being challenged, they all step up and fight.”

The trial drew so much attention that it was moved from a small-town courtroom to the county courthouse in White Plains.

Kennedy testified that she had no memory of the wild ride on the highway. “If I realized I was impaired, I would have pulled over,” she told the jury.

Prosecutors acknowledged she unintentionally took the drug zolpidem, but they told jurors she had to have known she was impaired and should have stopped driving.

When the jury forewoman read the verdict, Kennedy smiled broadly, hugged one attorney and clasped hands with another. Her family and friends applauded.

The charge was a misdemeanor that rarely goes to trial, but Kennedy was unwilling to settle the case and two judges refused to dismiss it.

Her family’s storied and sorrowful history crept into the trial when one of her lawyers asked about her upbringing and her work as president of the Robert F. Kennedy Center for Justice and Human Rights.

“My mother raised us because my father died when I was 8,” she said. “He was killed when he was running for president.”

Kennedy’s lawyer Gerald Lefcourt told jurors in his closing argument that Kennedy was “not seeking advantage because of her family.”

Another one of her lawyers, William Aronwald, said Friday that prosecutors told her they could not dismiss the case because “it would create the impression that Kerry Kennedy received special treatment because of her name.” He said prosecutors “were the ones who treated her differently because of who she is.”

The Westchester County district attorney’s office disputed the suggestion. “We prosecute 2,500 impaired driving cases annually in Westchester County,” the office said in a statement. “This case was treated no differently from any of the others.”

When Kennedy was asked after the verdict if she was angry that the case was pursued, she said: “Anger is the last feeling I’ve got right now.”

At a news conference outside, she noted that few people have the resources to fight such a charge.

“We need to take a hard look at our criminal justice system in the United States and make sure it really is just and everyone in our country has true access to justice,” Kennedy said.