Cash died eight days after open-heart surgery ended with severe complications, said Lou Robin, longtime manager for the couple. Her husband and family members were at her bedside.
Cash had co-writing credits on such hits as "Ring of Fire," "Long-Legged Guitar Pickin' Man and "Jackson." Performing as a duo, she and husband Johnny had hits with the 1964 reworking of Bob Dylan's "It Ain't Me Babe" and their fiery 1967 recording "Jackson." "Jackson" would win the couple a Grammy, as would their 1970 version of Tim Hardin's "If I Were a Carpenter."
For much of her life, Cash could have played second fiddle in a famous family. Instead, she shaped herself into a star in her own right, although she often put her family obligations ahead of career.
Her mother, aunt and uncle, performing as the Carter Family, were a pioneering force in country music's leap from regional sound to mainstream popular music in the 1920s. Hits such as "Will the Circle Be Unbroken?" and "Keep on the Sunny Side" made them royalty in the field. And when she became June Carter Cash, her husband's status again put her in a supporting role.
Valerie June Carter was born in Maces Springs, Va., on June 23, 1929, the second of three daughters to Mother Maybelle Carter, one of the founding members of the Carter Family trio, and Ezra Carter, a farmer. Young June was quickly brought into the family music circle and learned to play the autoharp. By the time she was 10, she and her sisters, Anita and Helen Carter, and their cousin, Janette Carter, were performing on the radio shows that beamed the family's music across much of rural America.
The elder Carters would typically perform traditional music and originals by A.P. Carter such as "Wildwood Flower," while the second-generation females would do versions of the day's hits as well as novelty tunes. By 1943, the original Carter act had disbanded, and the new incarnation of the family act -- Mother Maybelle and the Carter Sisters -- became a staple of radio and the Nashville stage.
By the 1950s, June Carter had established herself enough to become a solo artist, and she spent a year as an opening act for Elvis Presley. As a signature performer on the Grand Ole Opry radio show, she was not just a dynamic singer, but also a firebrand comic presence, with her playful lyrics and stage banter. She was married twice in the 1950s, first to honky-tonk singer Carl Smith, a relationship that led to the birth of daughter Rebecca, and then to Edwin "Rip" Nix, which produced another daughter, Rozanna, or Rosie. Both would take their mother's maiden name and perform music themselves, with the most success belonging to the eldest, performing under the name Carlene Carter.
The lasting love of her life, however, would be singer Johnny Cash, whom she married in March 1968. Their son, John Carter Cash, was born in 1970.
Presley had introduced June to the music of Cash, his label-mate briefly at Sun Records, in the mid-1950s, and after a chance meeting at the Opry late in that decade the future couple agreed to work together. By 1961 she was touring with Cash. Soon, Mother Maybelle and the other Carters joined the troupe of the famed Man in Black.
June Carter Cash retired from her solo career with the marriage to Cash (although her solo album debut, "Appalachian Pride," would not be formally released until 1975). The marriage was volatile in the early years as her husband grappled with drug addiction, but through the decades they became a famously devoted pair.
Her husband wrote of her in his autobiography: "What June did for me was post signs along the way, lift me when I was weak, encourage me when I was discouraged, and love me when I was alone and felt unlovable. She is the greatest woman I have ever known. Nobody else, except my mother, comes close."
Carter studied acting in the 1950s with director Elia Kazan and instructor Lee Strasberg. Besides her stage time on the "Johnny Cash Show" TV program, launched in 1969, she appeared in numerous television movies as well as such series as "Gunsmoke," "Little House on the Prairie" and "Dr. Quinn, Medicine Woman." She also appeared in Robert Duvall's 1997 film "The Apostle."
Through the years, her family connections and her own career gave Cash a fascinating trove of encounters. She was the godmother to Randall Hank Williams, better known as Hank Williams Jr., was a close friend of Patsy Cline and taught Presley how to tune a guitar.
In 1996, during a Johnny Cash show in a West Hollywood club, she performed a song she had written that spoke to her odyssey. The poignant "I Used to Be Somebody" reflected on the passings of friends (it mentions Presley, James Dean and Tennessee Williams, among others) and the fickle nature of fame.
Ironically, the song about faded glory earned her a career revival some 30 years after her retirement as a solo artist. The performance led directly to a new record deal and the 1999 album "Press On." The collection won a Grammy as best folk album, the only solo Grammy of her career.
"I've been really happy just traveling with John and being Mrs. Johnny Cash all these years," she told The Times in a 1999 interview. "But I'm also really happy and surprised that someone wanted me to make another album, and I'm real proud of what I've done."