After making her acting debut on the New York stage, Ms. Anspach moved to Hollywood and had a breakthrough role in the 1970 film “Five Easy Pieces,” opposite Nicholson.
Two years later, she portrayed Woody Allen’s haranguing ex-wife in “Play It Again, Sam,” delivering some of the comedy’s best lines:
“You’re a dreamer. You’re awkward. You’re clumsy. They can see how desperate you are. You know this. You said it yourself. Oh, face it, Allan. You may be very sweet, but you’re not sexy.”
In 1973, Ms. Anspach (pronounced ON-spock) starred in “Blume in Love,” a sophisticated film written and directed by Paul Mazursky, in which she played Nina, the straying wife of a divorce lawyer, played by George Segal.
“We have everything anybody could want, and we’re both miserable,” she tells Segal’s character, Stephen Blume.
Stephen: “I’m not miserable.”
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Nina: “Are you happy?”
Stephen: “I’m just not miserable. What more can anyone ask for? . . . I do the best I can.”
Nina: “No, you don’t. Neither do I.”
Soon afterward, Ms. Anspach’s career slowed down. She had roles in television but did not make another movie until “The Big Fix” (1978), with Richard Dreyfuss.
“I was getting reviews that compared me to Katharine Hepburn and Bette Davis,” she told People magazine that year. “But there were no Hepburn or Davis parts.”
Ms. Anspach, who periodically worked as a singer, reportedly accepted one of the lead roles in Robert Altman’s critically acclaimed 1975 film “Nashville” but quit the movie because she thought Altman was not showing enough respect for country music.
She later starred in “Montenegro” (1981), as the American wife of a Swedish businessman. In the film, she grows bored in her marriage and begins to hang out with a hard-living group of Yugoslav guest workers in Sweden.
New York Times critic Vincent Canby praised Ms. Anspach as “one of America’s most daring and talented actresses . . . who has yet to land a film role that shows her off to full advantage.”
“Montenegro” would be her last major film role. She played the wife of Dabney Coleman in “The Slap Maxwell Story,” a sitcom about a sportswriter that was canceled in 1988 after one season, but had few other high-profile parts.
Ms. Anspach taught acting and had occasional stage and TV roles, but she increasingly turned to Nicholson for financial support. They had worked together on “Five Easy Pieces,” in which Nicholson played a once-promising classical musician who was working as an oil-field roughneck. Ms. Anspach portrayed a pianist engaged to the brother of Nicholson’s character.
In the film, they had a steamy love scene, which they apparently reenacted in an off-screen romance. Ms. Anspach later said Nicholson was the father of her son, who was born in 1970.
In a 1994 Vanity Fair profile, Nicholson said he had one son, Raymond (with Rebecca Broussard), which prompted Ms. Anspach to write to the magazine, saying, “Our son, Caleb, is Jack’s older son and second oldest child.”
Within months, she received a letter from Nicholson’s business manager, asking her to repay more than $600,000 in loans or risk losing her house, on which Nicholson held the mortgage.
“He is trying to ruin me absolutely,” Ms. Anspach told People in 1996. “The only power he finally had over me was to have me sign my house over to him.”
She filed for bankruptcy and sued Nicholson for $1 million.
In a deposition, Nicholson said that he gave the loans to Ms. Anspach because “I’m a humanitarian” but that the legal proceedings caused him to view her with “mild antipathy.”
The dispute was settled out of court, and Ms. Anspach kept her home. Nicholson has never publicly acknowledged that he is the father of her son.
Susan Florence Anspach was born Nov. 23, 1942, in Queens, N.Y. Her father worked in a factory. Her mother, the daughter of a Wall Street banker, was disowned by her family for marrying a blue-collar worker.
Ms. Anspach studied theater at Catholic University in Washington and was the school’s homecoming queen in 1961. She later took classes at the Actors Studio in New York and appeared in off-Broadway productions with Robert Duvall, Dustin Hoffman and Jon Voight.
She had small parts on Broadway before landing the lead role in “Hair,” the landmark countercultural musical play that featured full nudity.
She later revealed that her male co-star in “Hair,” Steve Curry, was the father of her daughter. Both of her children were adopted by her first husband, actor Mark Goddard, whom Ms. Anspach later divorced.
She had a long-term romance in the 1970s with musician Robbie Robertson of the Band. Her second marriage, to musician Sherwood Ball, ended in divorce.
Survivors include her children, Catherine Goddard of Oakland, Calif., and Caleb Goddard of Bangkok; and three grandchildren.
Throughout her life, Ms. Anspach was active in social justice causes, marching with farmworkers rights activist Cesar Chavez, traveling with congressional delegations to Central America and demonstrating against apartheid in South Africa.
“The best actors get the truth from beginning to end,” Ms. Anspach told The Washington Post in 1973. “They don’t stop being the character when their lines are finished or while they’re waiting to speak the next ones. That’s what you try to achieve — that complete sense of character.”
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