From her lively questions to her scathing legal writing to her black velvet “dissent collar" she wore to indicate her disapproval of an opinion, Supreme Court Justice Ruth Bader Ginsburg built her career on the fight for women’s rights.

Before her days as a judge, she acted as general counsel for the American Civil Liberties Union (ACLU), where she argued over 300 gender discrimination cases—six before the Supreme Court—and cofounded the ACLU’s Women’s Rights Project. As a civilian, Ginsburg earned a reputation as a dogged advocate for gender equality. As a judge, first during 13 years as a U.S. Court of Appeals judge, then during 27 years as a Supreme Court Justice, she built upon that legacy.

Though she had a lifelong interest in gender equality, she was warned that pursuing a legal career that hinged on fighting discrimination against women was a non-starter. “The concern was that if a woman was doing gender equality, her chances of making it to tenure in the law school were diminished,” she told the New York Times’ Philip Galanes in 2015. “It was considered frivolous.”

Nevertheless, after being appointed Associate Justice by President Bill Clinton in 1993, Ginsburg authored some 200 opinions—and broke new ground for gender equality in the United States.

Here are some ways Ginsburg fought for gender equality:

“Equal Protection” for women and men means males cannot be preferred to females.

Ginsburg took advantage of prior civil rights rulings on race—and male plaintiffs—to help illustrate why the Supreme Court should end gender discrimination. Many of her cases hinged on the Fourteenth Amendment’s Equal Protection Clause, which provides that people shall be equally protected by U.S. laws. Through a barrage of smaller cases, she chipped away at discriminatory laws.

But it was Reed v. Reed, a 1971 case for which Ginsburg wrote the plaintiff’s brief, that relied on the 14th Amendment. A minor, Richard Lynn Reed, known as “Skip,” died and his mother wanted to be designated as the administrator of his estate. Sally and her husband, Cecil Reed, had separated. Despite Sally filing a petition first, Cecil’s application was automatically approved because of an Idaho statute that stated that “males must be preferred to females” when there was more than one qualified person available to administer someone’s estate.

Ginsburg argued that this violated the Equal Protection Clause. The Supreme Court unanimously agreed and struck down the Idaho statute. It was the first time the Court had ever applied the Equal Protection Clause to a law that discriminated on the basis of gender.

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Air Force Lt. Sharon Frontiero, 23, filed suit against the Air Force claiming sexual discrimination in 1971 after not receiving the same military allowances as her male counterparts.

Gender-based discrimination hurts men too—Ginsburg argues her first case before the Supreme Court.

Another case that hinged on gender discrimination and government benefits was Frontiero v. Richardson. The 1973 case was the first Ginsburg argued before the Supreme Court. When a woman in the U.S. Air Force applied for benefits for her dependent husband, she was told she’d have to prove he was a dependent, even though men in the Air Force didn’t have to prove that their wives were dependent on them.

In an amicus brief, Ginsburg used the statute to argue that gender-based discrimination hurt men, too. “Why,” she asked the Court during oral arguments, “did the framers of the 14th Amendment regard racial [discrimination] as odious? Because a person’s skin color bears no necessary relationship to ability. Similarly...a person’s sex bears no necessary relationship to ability.”

A plurality of the Supreme Court found the benefit policy violated the Constitution and argued that, because of the United States’ long history of gender-based discrimination, the court should use a strict standard of judicial scrutiny for laws that used sex as a classification.

A women’s right to equal beer?

In Craig v. Boren, a 1976 case, Ginsburg took a roundabout road to protecting women’s rights by arguing that women shouldn’t be allowed to purchase beer at an earlier age than men. The law in question was an Oklahoma statute that allowed women to purchase low-beer at age 18 but that forbade men to purchase it before they turned 21.

Ginsburg filed an amicus brief on behalf of the ACLU, honing in on the old-fashioned gender stereotypes embodied by the law. The court agreed, determining for the first time that laws that hinged on sex should pass “intermediate scrutiny”—a standard of judicial review that hinged on whether the law was related to a legitimate governmental objective. There are no fair trials if Jury Duty is optional for women.

In 1979, Ginsburg argued Duren v. Missouri, a case in which a Missouri man accused of murder argued he couldn’t get a fair trial because of a law that made jury service optional for women. She told the court that such exemptions didn’t just make the jury pool unfair; it devalued women’s contributions to juries.

The Court agreed 8-1 and held that the underrepresentation of women on local juries was due to their exclusion from the jury selection process. “Exempting all women because of the...domestic responsibilities of some women is insufficient justification for their disproportionate exclusion,” the court ruled.

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Lilly Ledbetter in front of the U.S. Capitol, 2008. Ledbetter worked in an Alabama Goodyear tire factory as a night-shift supervisor for nearly 20 years, and did not make as much as her male counterparts who did the same work.

Equal Pay for Equal Work—Ginsburg joins the fight from behind the bench.

Ginsburg had argued for equal rights for women as an attorney. As a Justice, she argued just as eloquently from behind the bench, even setting the stage for groundbreaking legislation. In Ledbetter v. Goodyear Tire & Rubber Co., Lily Ledbetter sued her employer for what she alleged was discriminatory pay. Though she started out at the same salary as her male coworkers, by the end of their tenure at Goodyear, she made thousands less a year than other men at her job. Ledbetter claimed this was because of discriminatory employee evaluations and sued Goodyear based on Title VII of the Civil Rights Act of 1964, which holds that covered employers can’t discriminate on the basis of gender, and the Equal Pay Act.

The case hinged on whether Ledbetter had the right to sue years after the alleged discrimination took place. The 5-4 majority held that she didn’t file her claim in a timely manner. But Ginsburg and three of her colleagues disagreed. In her 2007 dissent, which she read from the bench (a rare move for any justice), she argued that the Civil Rights Act’s 180-day time limit shouldn’t apply in the case of discriminatory pay since gender-based discrimination can happen gradually. “A worker knows immediately if she is denied a promotion or transfer,” said Ginsburg. “Compensation disparities, in contrast, are often hidden from sight.”

This “cramped” interpretation of the law, she argued, was incompatible with the law’s purpose. “The ball is in Congress’ court.” Congress took up Ginsburg’s battle cry. In 2009, President Obama signed the Lily Ledbetter Fair Pay Act, which amended the Civil Rights Act of 1964 to reset the statute of limitations on equal-pay lawsuits with every paycheck.

Ginsburg stood firm on a woman’s right to choose.

Throughout her time on the Supreme Court, Ginsburg stood firm on a woman’s right to have an abortion. In her 2016 concurrence to the Whole Women’s Health v. Hellerstedt opinion, in which the Court ruled that Texas cannot restrict abortion services that unduly burden women who seek an abortion, she delivered a rousing defense of a woman’s right to choose.

She did so alone. No other justice signed on to her concurrence, in which she wrote that “many medical procedures, including childbirth,” are far more dangerous than abortion and said that the Texas law restricting abortions was “beyond rational belief.” The law “cannot survive judicial inspection,” she wrote in the scathing document. The verdict was seen as a victory for women’s reproductive rights, and another example of Ginsburg’s staunch defense of women.