Growing up in Kew Gardens, Queens, in the 1960s, Phyllis Graber played stickball, handball and baseball, eventually falling for tackle football, which she played in Forest Park, the only girl who was interested. Concerned that she was “developing,” her parents encouraged her to shift her focus to something demanding less savagery. She found this vaguely ridiculous but chose tennis, a sport in which she excelled. While she would have been invaluable on any girls’ tennis team, Jamaica High School in 1970 did not have one.

With little ambivalence, Phyllis asked to play on the boys’ team. Against the vogue for male chauvinism, both the coach, who recognized her talent, and the team members themselves said they would welcome her. But Board of Education rules governing school athletics did not permit the inclusion of girls in boys’ sports. So at 16, Ms. Graber filed what turned out to be an enormously influential complaint with New York City’s Commission on Human Rights.

This year’s U.S. Open unfolds within the context of landmark anniversaries in the history of women’s tennis, a chronology in which Phyllis Graber played an important if forgotten part. On Tuesday in Flushing Meadows, Michelle Obama honored Billie Jean King’s work to establish equity in the distribution of prize money, which had a turning point at the Open 50 years ago. September will also mark a half-century since the “Battle of the Sexes,” one of the most watched sporting events of all time, the match that had Ms. King defeating Bobby Riggs as both a tenacious adversary of his baseline game and blowhard prejudices.

The early 1970s were a watershed moment for women’s tennis and the role it held in advancing equality more broadly. Ms. Graber made her case before the Commission on Human Rights in September 1970, whenits chairwoman was the civil rights leader and future congresswoman Eleanor Holmes Norton.

Before Ira Glasser, who would later become the director of the American Civil Liberties Union, filed the official complaint, he spent six months unsuccessfully petitioning the Board of Education to shift its policy. In practice sessions, Ms. Graber had beat two boys who made the team. But the hearing — one of the era’s first on the rights of women — made the difference. In February 1971, the board voted to allow girls to compete with boys in non-contact sports. Ms. Graber joined the team, where by her own admission, she was not the best player but could still claim many wins.

Phyllis Graber eventually became Phyllis Graber Jensen and lives with her husband in Maine, where she works as the director of photography and video for the communications office at Bates College. In the moment, she did not realize what she helped propel, she told me recently. At the hearing Ms. Holmes Norton said that she was disappointed that other girls were not waging similar campaigns. But soon around the country, other girls did challenge these norms until the passage of Title IX in 1972 opened up a new world of opportunities for girls’ sports.

At Cornell, where Ms. Graber played on the women’s tennis team, she met another woman who had also secured a position on a boys’ team. Between 1970 and 1972, the number of high school girls participating in team sports increased from 300,000 to 800,000.

“I had a gradual awakening based on what I encountered in school, in Ms. magazine, in what was happening in the world around me,” Ms. Graber Jensen told me. “If I had been born 10 years earlier, I would have faced a much grimmer experience. I think my parents were exceptional in how they encouraged me. I think back on my father. He was raised in a traditional home. He bounded ahead of those ideas on his own.”

I encountered the Phyllis Graber story by chance through a passing reference in a new book, “Radical Play,’’ by the historian Rob Goldberg, which looks at the way that the social disruptions of the 1960s and ’70s were reflected in the manufacture of children’s toys. The book traces a direct line from the Graber case to the emergence of an androgynously named teenage doll, Dusty, introduced as an anti-Barbie by the Kenner toy company in 1974. In an earlier effort to capitalize on the women’s movement, the company tried and failed, Mr. Goldberg recounted, to market a single-mom doll packaged with a baby.

Praised by Letty Cottin Pogrebin, co-founder of Ms., as a doll that “actually does something,” the flagship Dusty played tennis — other versions of the doll came with softball, volleyball and golf gear. Dusty’s chest was smaller than Barbie’s, her waist was thicker and her feet were flat. What really distinguished her from other dolls, Mr. Goldberg writes, was a trademarked “spring-loaded action” that allowed her to swing a racket.

By 1976 that capacity was gone. The invincibility of Barbie, which the outsize success of the current film does more than enough to corroborate, was apparent even then, even as the world seemed to be shedding its anachronisms. Dusty in her initial form did not prove commercially viable, so the company tweaked her appearance to make it more feminine, with fewer freckles, longer hair and a reconstruction that left her unable to swing anything. Kenner went further. As if it were really in the business of appealing to every middle-aged guy who had dumped his wife for someone hotter, the company allowed the old version of Dusty to be traded in for the new inert one.

The lesson was that taste, especially as it expresses itself in consumer habit, does not necessarily follow ideology. Malibu Barbie could not have become one of the best-selling toys in the world in the ’70s if thousands of newly liberated women hadn’t bought it for the girls in their lives regardless of the incompatible messaging. Phyllis Graber played with Barbie dolls when she wasn’t playing tackle football — and she had a working mother.

So many of our conversations around gender are complicated and stifled by an inability to understand the human impulse toward what might seem like self-contradiction. When the Board of Education made its decision in the Graber case, observers were surprised to learn that the single dissenting vote came from the only woman on the board, Mary Meade, someone with her own pioneering narrative. She had received a doctorate in political philosophy and had become the first woman to serve as principal of a coed high school in New York City, all before 1940. Apparently, there was some ground that she felt did not need breaking.