The following obituary from the Guardian is by Dave Laing

Peter, Paul and Mary were the most successful vocal group of the American folk revival of the 1960s. In particular, they were responsible for bringing the music of Bob Dylan to a mass audience through their hit record of his Blowin' in the Wind. With her powerful voice and long blonde hair, Mary Travers, who has died aged 72, was the focal point of the trio.

She was born in Louisville, Kentucky, but her journalist parents moved to Greenwich Village, New York, when she was two years old. She attended progressive private schools and recalled that folk music was "a very integral part of the liberal left experience. It was writers, sculptors, painters, whatever, listening to Woody Guthrie, Pete Seeger, the Weavers. People sang in Washington Square park on Sundays and you really did not have to have a lot of talent to sing folk music." At high school, she was a member of the Song Swappers, an ad hoc chorus that accompanied Seeger on several recordings. After graduation, Travers had no ambition to perform, although she occasionally sang in folk clubs and appeared in the comedian Mort Sahl's Broadway show The Next President, in 1958.

The group was formed in 1960 by the folk impresario Albert Grossman, who saw a commercial opportunity for a male and female trio to emulate the success of the all-male Kingston Trio. He already managed Peter Yarrow and Travers brought in Noel Stookey, a stand-up comedian and singer, who adopted his middle name, Paul, for the purposes of the new group. Travers once said that the name was also inspired by the folk-song lyric "I saw Peter, Paul and Moses, playing ring around the roses".

Grossman hired the arranger and producer Milt Okun to rehearse the trio. He smoothed out their harmonies and trained their individual voices. "I had a tendency to sometimes go flat and Milt fixed it," said Travers. Six months later, in 1961, Peter, Paul and Mary made their professional debut at the Bitter End coffee house, Greenwich Village. Yarrow explained that Grossman's plan was for Travers to be a kind of American Brigitte Bardot, a "sex object for the college male", maintaining her mystique by not talking to audiences.

A recording contract with Warner Bros soon followed, although the company's executives were nervous about the "beatnik" image projected by Travers's long hair and casual clothes and the men's goatee beards. Peter, Paul and Mary's contract gave them an advance of $30,000 and control over album cover art. The first, eponymous album was issued in 1962. It soon rose to No 1 in the US and sold more than 2m copies there. The album also produced two hit singles with the traditional song Lemon Tree and If I Had a Hammer – a spiritual associated with Seeger. Puff, the Magic Dragon, a children's song co-written by Yarrow which was sometimes claimed to contain coded drug references, was another big early hit.

By 1963 Grossman was also managing Dylan, and Peter, Paul and Mary recorded several of his songs, replacing the composer's idiosyncratic diction with their punchy but conventional harmonies. In the summer of that year, the trio had massive hits with Blowin' in the Wind, which also made the UK Top 20, and Don't Think Twice, It's All Right. In that year, too, the group were headliners at the Newport folk festival, where they sang Blowin' in the Wind alongside Dylan, Seeger and Joan Baez.

Peter, Paul and Mary were strongly committed to civil rights. Travers often said that Blowin' in the Wind was her favourite song and that her most important performance was in Washington at the climax of Martin Luther King's march on Washington. "Imagine singing that song in front of a quarter of a million people, black and white, who believed they could make America more generous and compassionate in a non-violent way."

The group's success also led to an invitation to sing at the official celebration of president John F Kennedy's second year in office. Travers had to buy a long dress and long gloves for the occasion.

Although acoustic music and the folk revival was eclipsed in the mid-1960s by rock and folk-rock, Peter, Paul and Mary remained popular throughout the decade. They recorded hit singles with a song by the rising Canadian star Gordon Lightfoot, For Lovin' Me, the tongue-in-cheek I Dig Rock and Roll Music, part-written by Stookey, and another Dylan piece, When the Ship Comes In. Their final hit, and their only US No 1 single, was the John Denver composition Leaving on a Jet Plane, in 1969. It was also their biggest UK hit, reaching No 2 in 1970.

When the group split up that year, Travers continued as a soloist. She recorded five albums in the 1970s, though none emulated the trio's success. She also hosted an interview-based radio show for several years. The trio eventually reunited in 1978 to play a benefit concert for anti-nuclear causes. They toured and recorded occasionally over the next two decades. The title song of their 1986 album, No Easy Walk to Freedom, was dedicated to Nelson Mandela. In that year, Peter, Paul and Mary performed at the Martin Luther King birthday celebrations in Washington, reprising Blowin' in the Wind with Dylan.

In 2005, Travers was diagnosed with leukaemia and underwent bone marrow transplant surgery. She was able to return to performing, but earlier this year her condition worsened. She is survived by her fourth husband, Ethan Robbins, two daughters, Alicia and Erika, from a previous marriage, and two grandchildren.

• Mary Allin Travers, singer, born 9 November 1936; died 16 September 2009