Now, after a spectacular run of more than half a century which she began as the so-called Today girl, Walters has said goodbye to ABC's The View.
Oprah Winfrey and former Secretary of State Hillary Rodham Clinton surprised Walters as she taped her final edition.
"I can't believe this day has come and I can't believe it's for real," Clinton told Walters.
Winfrey told her: "You're the reason I wanted to be in television."
Film star Michael Douglas, a longtime friend and frequent subject for Walters' interviews, also dropped by for the tribute.
Walters retired from on-air work, having lived and broadcast so long in the mass media age that she outlasted the term "newswoman".
At 84, Walters even outlasted most of the technology that brought her into America's living rooms.
She was the first female anchor of an evening news programme when she joined ABC in 1976 and went on to become a living legend of television journalism.
She has interviewed every US president and first lady since Richard Nixon.
Her list of interviewees includes not only some of the most pivotal figures of recent history - Boris Yeltsin, Margaret Thatcher, Indira Gandhi, Saddam Hussein, Menachem Begin and Vladimir Putin - but also a galaxy of A-list stars such as Katharine Hepburn, Michael Jackson, Angelina Jolie and Harrison Ford.
Whether head of state or Hollywood star, Walters mastered the art of the emotional interview, often coaxing her subjects into opening up on screen in a way that they had rarely done before.
She was also relentless in chasing down the story of the day. Most recently she pursued an interview with the disgraced owner of the Los Angeles Clippers basketball team, Donald Sterling, who triggered outrage after making a series of racist remarks to his girlfriend.
Beamed in from Los Angeles, Walters told 20/20 co-hosts Elizabeth Vargas and David Muir about a hectic day spent trying to get Sterling to submit to an on-camera interview.
Walters seemed disappointed, exasperated even.
But still the professional, she served up the booby prize - a seven-minute interview with his estranged girlfriend V Stiviano.
The interview, which aired on May 2, will not be remembered for anything much, except maybe that it will be Walters' final "get" in an endless list of them. It's a long way from her interview with Fidel Castro in 1977. It's a long way from her following President Richard Nixon to China in 1972.
It's even a long way from the two-hour, 1999 interview she did with Monica Lewinsky that lured in more than 50 million viewers - the sort of non-football television ratings that simply can't be had any more.
That interview remains her biggest ratings success.
Walters has also shown an ability to laugh at herself, making a surprise recent appearance on the comedy sketch show Saturday Night Live, which has lampooned her mercilessly as "Baba Wawa".
It was a name given to her by comedian Gilda Radner and later riffed on by subsequent female cast members,
The key to a good interview, according to Walters, is simple.
"Do not be afraid to ask the tough question," she said.
"Like 'If you were a tree, what tree would you be?'" she quipped, referring to a famous question she once posed to screen idol Katharine Hepburn.
Walters made a household name for herself on Today before her groundbreaking move to ABC in 1976.
In 1979, she fronted the television news show 20/20, while continuing to present news on occasion and moderating set-piece events such as one of the 1984 presidential debates.
In 1997, she launched The View, a daytime talk show pitched at women of diverse backgrounds featuring an all-female panel discussing issues of the day.
She has been married four times, including twice to the same man, Merv Adelson, who she has also divorced twice. She has one adopted daughter.
At a ceremony last week, which saw ABC television rename their New York office in her honour, Walters listened as Disney chief Bob Iger hailed her "tremendous importance to the industry".
Walters said she wanted to be remembered for her role in opening doors for women. "People ask me very often, 'What is your legacy?' And it's not the interviews with presidents, nor heads of state, nor celebrities," she said.
"If I have a legacy - and I've said this before and I mean it so sincerely - I hope that I played a small role in paving the way for so many of you fabulous women who are here tonight." She added: "And my longevity on the air - that one can work as long as I've worked, and still be vital.
"It demonstrates that there's no age limit for people. And there shouldn't be."
She continued with a joke: "I'm walking away from a career of 38 years, just at ABC News. So I think, 'What's the next milestone?' The next milestone is death! Oh, thanks a lot!"
In her dotage, Walters lost some of her edge and opened herself to criticism of being too gentle or too allied with her subjects.
Ever since America swooned over her US$1 million contract to jump from NBC to ABC in 1976, her own fame became difficult to separate from the fame of her interviewees.
But as Walters' career has made clear, she is nothing if not defiant, with a lifetime spent challenging assumptions and naysayers.
Just ask Bill Geddie, who continues as co-executive producer of The View with Walters in a partnership that was born 25 years ago.
Back then, Geddie, a former Good Morning America producer in his early 30s, had grabbed her offer to produce Walters' prime-time specials - and did it, he recalls, against everyone's advice. "They said, 'She's got two, maybe three more years. Nobody's gonna watch a woman over 60."' And he laughs.
"I don't think they realised, even by that time, how driven she was, how good she was, how this was not just a job for her. This was her life."
Geddie acknowledges that now, finally, Walters faces a profound change. "But do I think we've seen the last of Barbara Walters? Absolutely not," he said.
Agence France-Presse, Associated Press, The Washington Post