In Paul Mazursky's era-defining 1978 movie, Ms. Clayburgh played Erica, a seemingly content housewife and mother who finds herself unexpectedly divorced after 16 years. She reels from her husband's sudden confession of infidelity — famously throwing up in the street shortly after getting the news — but finds a new life, a new lover in Bohemian painter Alan Bates, and an independence which both confuses and delights her. Upon the movie's release, Ms. Clayburgh became a filmic representation of the Women's Movement and its social repercussions.

Ms. Clayburgh was nominated for an Academy Award and won the Best Actress Award at the Cannes Film Festival for her performance and, for the next few years, along with fellow free spirit Diane Keaton, was the "It" girl in Hollywood. Willowy, ash-blonde, blue-eyed and elegant, she appeared in the following years in Alan J. Pakula's "Starting Over," navigating the dating waters with newly divorced Burt Reynolds (her second Oscar nomination); "It's My Turn," about a woman who gets involved with an ex-pro baseball player; and "I'm Dancing as Fast as I Can," about a successful single documentarist whose life spirals out of control due to drug addiction. During this time, she also turned down the lead in "Norma Rae," another iconic film of the time centered on a strong female.

"A woman came up to me after one of the screenings the other day with tears pouring down her face," she once related, "and sobbed, 'My God, you've defined my entire life for me on the screen.' I don't exactly know why, but people always seem to see echoes of their own lives in my films. They really feel for me."

By the early '80s, however, the magic was gone, and Ms. Clayburgh appeared in fewer, and less successful, films.

New York City-born Jill Clayburgh's career began at the Charles Street Repertory Theatre in Boston. After making her Broadway debut in The Sudden & Accidental Re-education of Horse Johnson in 1968, she attracted attention as the love interest in two hit musicals: Hannah Cohen in The Rothschilds, the match of Nathan Rothschild in the Harnick and Bock 1970 musical; and two years later, as Catherine, a mate for the aimless hero of Stephen Schwartz's hit musical Pippin. In the latter, she originated the songs "Kind of Woman" and "I Guess I'll Miss the Man."

	Clayburgh in The Clean House
	photo by Joan Marcus

Ms. Clayburgh stayed on to appear in the brief Broadway premiere of Tom Stoppard's Jumpers, but thereafter she devoted herself to Hollywood, earning a reputation as a popular modern stylist of screwball comedy in "Semi-Tough" and "Silver Streak." She married playwright David Rabe in 1979. Their daughter, Lily Rabe, has become a prominent, and busy, stage presence in the last few years (she is Portia in Broadway's current The Merchant of Venice, which features Al Pacino as Shylock; Rabe missed several recent performances during her mother's decline).

Coinciding with her daughter's rise in her profession, Jill Clayburgh returned to the New York stage, appearing in a large number of productions in a short period of time, including Richard Greenberg's A Naked Girl on the Appian Way (2005); a revival of Neil Simon's Barefoot in the Park (2006); Sarah Ruhl's The Clean House at Lincoln Center Theater (2007); The Busy World Is Hushed at Playwrights Horizons (2007); and The Exonerated at Bleecker Street Theatre.

Reviewing her in The Clean House, the New York Times wrote, "The poignance and dithery charm in her portrayal of Virginia are perfectly calibrated, as unhappiness and sororal envy evolve into compassion."

Her reemergence as a stage actress was very much tied to her daughter's blossoming career. "Israel Horovitz has this theatre in Massachusetts, Gloucester Stage," she told Playbill in 2005. "It's right on the beach. I prepare by looking out the back at the water. It's so beautiful. He said to me, 'Let's do something,' the way people say, 'Let's have dinner.' I said, 'Well, write something for me. Write something for me and Lily.' He said, 'Okay.' And he did. It was called Speaking Well of the Dead. Then Frank Pugliese wrote something for us, The Crazy Girl, and we did that. I really enjoyed doing those plays. They got me excited about doing theatre again."

For a time, mother and daughter roomed together in a New York apartment, both plying their trades on different stages.

In 2007, she took on a role in the ABC drama "Dirty Sexy Money," which has since been canceled. Ms. Clayburgh is survived by her husband, daughter, and a son, Michael.