Phyllis Schlafly, a conservative activist, lawyer and author who is credited with almost single-handedly stopping the passage of the Equal Rights Amendment in the 1970s and who helped move the Republican Party toward the right on family and religious issues, died Monday at her home in St. Louis. She was 92.

Her daughter, Anne Cori, said Mrs. Schlafly had been ill with cancer for some time.

A champion of traditional, stay-at-home roles for women, Mrs. Schlafly opposed the ERA because she believed it would open the door to same-sex marriage, abortion, the military draft for women, co-ed bathrooms and the end of labor laws that barred women from dangerous workplaces.

The brief Equal Rights Amendment (“Equality of rights under the law shall not be denied or abridged by the United States or by any state on account of sex”) was anti-family and anti-American, she said. Equality, she added, would be a step down for most women, who she said are “extremely well-treated” by society and laws.

Mrs. Schlafly was almost too late to stop the amendment’s passage: By early 1972, when she first published her objections, it had just passed Congress, and 30 of the necessary 38 state legislatures had ratified it.

Mrs. Schlafly, an experienced anti-communist Republican Party activist, quickly organized the opposition. The effort began operating under the name “Stop ERA” and later became a national organization called the Eagle Forum, which Mrs. Schlafly dubbed an alternative to women’s liberation. In 1973, the U.S. Supreme Court issued its decision on Roe v. Wade, legalizing abortion. Suddenly, a huge constituency of ­conservative, family-oriented churchgoers was energized to engage in politics.

Binding together fundamentalists, evangelicals, Catholics, Mormons and Orthodox Jews, Mrs. Schlafly realized that she could direct a movement of people who believed the family and traditional values were under attack. A best-selling author, radio commentator and an excellent debater, she barnstormed the country, speaking before clubs, church organizations and 30 state legislatures.

By the time the deadline for passage of the ERA arrived in 1982, 15 states had rejected it and five others had rescinded their ratifications. The measure fell three states short of passage.

Mrs. Schlafly staged a festive burial party at Washington’s Shoreham Hotel and told a crowded news conference that the ERA “is dead for now and forever in this century.” The nation could enter “a new era of harmony between women and men,” she said.

Just as her public life didn’t begin with the ERA, it didn’t end with its defeat. The battle over the amendment helped launch the family values, antiabortion movement in the United States, and Mrs. Schlafly continued to be one of its standard bearers, as well as supporting causes such as opposition to illegal immigrants, federal judicial activism, ballots in languages other than English, the Title IX rules that required equal treatment of girls and boys in sports, and “privacy-invading questions” on the census. Secretaries, stewardesses and other women fighting for pay of comparable worth were simply “envious” of the wages of janitors and truck drivers, Mrs. Schlafly said.

Always quotable, her opinions could outrage and provoke even members of her own political party’s establishment. When President Ronald Reagan’s surgeon general, C. Everett Koop, tried to introduce AIDS education to public school curriculums in the 1980s, Mrs. Schlafly likened it to “the teaching of safe sodomy.” She called sex education “a principal cause of teenage pregnancy.”

Reagan-appointed Supreme Court Justice Anthony M. Kennedy ran afoul of Mrs. Schlafly in 2005, when his opinion questioning capital punishment for juveniles seemed to her to be grounds for impeachment. She said during the 2010 Conservative Political Action Conference in Washington that no woman, including former Alaska governor Sarah Palin, was yet ready to be president, although she had cheered Palin’s selection as the Republican’s 2008 vice-presidential nominee, calling her as “an exemplar of all that is good and true.”

Phyllis Schlafly talks with Missouri delegate Juanita Crosby at the 1992 Republican National Convention in Houston. (Barry Thumma/Associated Press)

Mrs. Schlafly was an attorney who built her own media empire, writing or editing 20 books. She published a monthly newsletter, the Phyllis Schlafly Report, wrote a syndicated newspaper column, produced radio commentaries and anchored a radio talk show. She also was a regular lecturer on the college circuit.

Mrs. Schlafly was the subject of two biographies, Carol Felsenthal’s “The Sweetheart of the Silent Majority” (1981) and Donald Critchlow’s “Phyllis Schlafly and Grassroots Conservatism” (2006).

Reagan appointed her to the Commission on the Bicentennial of the U.S. Constitution, and ­Ladies' Home Journal named her one of the 100 most important women of the 20th century.

An indication of her continuing relevance and her ability to stir up emotions came in 2008 when hundreds of students protested when her alma mater, Washington University in St. Louis, granted her an honorary diploma.

Well-spoken, self-assured, dress­ed like an affluent homemaker, “with a hairdo like a treble clef,” as Ginia Bellafante of the New York Times said in 2006, Mrs. Schlafly drove feminists nuts.

A woman’s most important job is to be a wife and mother, Mrs. Schlafly repeatedly said, even as she employed a full-time housekeeper to care for her six children. She said she was never away from home overnight and often took her infants with her to speaking engagements. In 1992, her home state of Illinois named her its Mother of the Year.

“I’d like to thank my husband, Fred, for letting me be here today,” she told a crowd of 11,000 at a pro-family gathering in 1977. “I like to say that because it irritates the women’s libbers more than anything.”

In 1981, speaking at a Senate labor committee hearing on sexual harassment in the workplace, Mrs. Schlafly said that “men hardly ever ask sexual favors of women from whom the certain answer is ‘No.’ Virtuous women are seldom accosted by unwelcome sexual propositions or familiarities, obscene talk or profane language.”

She never shrank from battle, agreeing countless times to debate well-known feminists such as Betty Friedan, Gloria Steinem and Eleanor Smeal. In one such faceoff, at Illinois State University in 1973, the often-volatile Friedan called Mrs. Schlafly a traitor to her sex and said she would like to burn her at the stake. Four years later, after Mrs. Schlafly implied that all the women at a women’s conference in Houston were gay, Steinem, one of the few feminists who could match her quotes, retorted, “If we’re all lesbians, where are we getting all these unborn babies to kill?”

Born Phyllis McAlpin Stewart on Aug. 15, 1924, in St. Louis, she was the daughter of a librarian who supported the family of four when Phyllis’s father could not find work during the Depression.

Mrs. Schlafly attended two years of college at Maryville College of the Sacred Heart, but the school was not rigorous enough for her, she later said, so she paid her way through Washington University by working 48 hours a week in a World War II ordnance plant, firing machine guns to test the ammunition.

She graduated Phi Beta Kappa and then earned a master’s degree in political science in 1945 from Radcliffe College, Harvard University’s sister school for women. She headed to Washington for a year to do research for what is now the American Enterprise Institute, then went back to St. Louis to work on a congressman’s reelection campaign and to be a research director at two local banks.

She said she was “saved from the life as a working girl” by marrying wealthy lawyer Fred Schlafly in 1949. She quit her job and became a community volunteer and Republican Party activist. In the early 1950s, she did research for Sen. Joseph R. McCarthy, the Wisconsin Republican who railed against Communist infiltration into the U.S. government.

Mrs. Schlafly won the Republican nomination for Congress from Alton, Ill., on her first try in 1952, presenting herself as a housewife. She lost in the general election to the incumbent. She was a delegate to the 1956 Republican National Convention, and in 1960 she tried again for Congress, this time as a write-in candidate. At the 1960 Republican National Convention, she helped lead a revolt of conservatives against an anti-segregation and anti-discrimination plank in the party’s platform.

She and her husband also founded the Cardinal Mindszenty Foundation to alert the world to the dangers of communism. She published pamphlets that compiled right-wing essays and in 1962 became a radio commentator on a program carried by 18 stations. The atomic bomb, she said, was “a marvelous gift given to our country by a wise God.”

An enthusiastic supporter of Barry Goldwater, the Republican nominee for president in 1964, Mrs. Schlafly wrote her first book, “A Choice Not an Echo,” attacking the elite, East Coast kingmakers of the party who ignored the grass-roots conservatives who were Goldwater’s base. She published it herself as a mail-order paperback, and it sold more than 3 million copies before Election Day.

The success inspired her to write a series of books about national defense, in partnership with retired Navy Adm. Chester Ward. One accused Defense Secretary Robert S. McNamara and presidential advisers McGeorge Bundy and Walt Rostow of deliberately weakening the U.S. military so that the Soviets could overwhelm the United States. Another, written by herself, contended that communists instigated the urban riots in 1967.

Mrs. Schlafly also rose in the ranks of the National Federation of Republican Women, becoming first vice president. She was in line to rise to president, but Goldwater’s loss to Lyndon B. Johnson in the presidential race brought a resurgence of the party’s liberal wing, and Mrs. Schlafly was outmaneuvered for leadership of the group.

She founded the Eagles Are Flying, a separate group for her supporters in the National Federation of Republican Women, as well as a trust fund for conservative candidates and her own newsletter.

In 1970, she tried a third time to win election to Congress but again lost to an incumbent.

Her decision to enter law school in the early 1970s was temporarily halted by the objections of her husband, although he had encouraged all their children to go to law school. He changed his mind two weeks later, and she graduated from Washington University’s law school in 1978.

In 1993, after 44 years of marriage, her husband died, and Mrs. Schlafly moved back to St. Louis from their longtime home in Alton.

Survivors include six children: Cori, Bruce Schlafly and Liza Forshaw, all of St. Louis; John Schlafly of Alton, who came out as gay in 1992; Roger Schlafly of Santa Cruz, Calif.; and Andrew Schlafly, of Far Hills, N.J., who started Conservapedia in 2006 as a re­action against perceived liberal bias in Wikipedia; 16 grandchildren; and three great-grandchildren.

Mrs. Schlafly’s opposition to the ERA developed only after a friend invited her to speak about the proposed constitutional amendment to a Darien, Conn., book club in early 1972. Until then, she said later, she was unaware of the then-50-year-old proposal.

At first, she recalled, “I don’t even know what side I’m on . . . I figured ERA was something between innocuous and mildly helpful.”