Emily Miller remembers learning about Title IX during history class, probably sometime in junior high. She's a little fuzzy on the details, including how and why it came about. Every time she steps on the soccer field, though, she feels its effect.

At 16, Miller can't even imagine who she'd be without the game. She's played since kindergarten, and credits soccer for her independence and self-confidence. Now a starter on the varsity team at New Trier High School in suburban Chicago, she's proud when someone describes her as "the athlete" or "the soccer player."

"Soccer," she said, "is what makes me Emily Miller."

As Title IX celebrates its 40th anniversary tomorrow, the WNBA is in its 16th season, Hope Solo and Natalie Coughlin will be two of the biggest names at the London Olympics and participation numbers for women in college and high school athletics are at an all-time high. But perhaps the greatest legacy of the legislation originally intended to prohibit discrimination in education is found in Miller and the hundreds of thousands of girls like her: a generation of young women growing up strong and self-assured because of their participation in sports. A generation for whom sports is so ingrained in their lives, they can't fathom being on the sidelines.

A generation for whom Title IX is ancient history, if they remember it at all.

"That's the way it should be," said former Sen. Birch Bayh, who co-authored and sponsored Title IX. "It should be a given. That's what we were trying to accomplish."

Title IX reads: "No person in the United States shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or be subjected to discrimination under any education program or activity receiving federal financial assistance."

The words "sports" or "athletics" are not even mentioned in Title IX. At a time when women earned nine percent of all medical degrees and just seven percent of law degrees, Bayh and the other Title IX supporters were simply hoping to provide more opportunities for women in higher education, give them a better shot at higher-paying jobs.

"It was clear that the greatest danger or damage being done to women was the inequality of higher education," Bayh said. "If you give a person an education, whether it's a boy or girl, young woman or young man, they will have the tools necessary to make a life for their families and themselves."

But just as admissions numbers and financial aid fell under the broad definition of "education program," so, too, did athletics.

"Sport is an educational opportunity. You learn about yourself and the world through sport," said Angela Ruggiero, president-elect of the Women's Sports Foundation and a member of the 1998 U.S. team that won the first Olympic gold medal in women's ice hockey.

It wouldn't be enough for schools to tack sign-up sheets on a bulletin board and count that as a team, or clear out a storage closet and call it a locker room. Title IX called for equal opportunity to play, and that meant schools had to offer scholarships and provide the same access to equipment, coaching and facilities.

'A tremendous accident'

Some prominent coaches and athletic directors, worried that Title IX would gut football, pushed to have revenue sports - namely football - excluded from the compliance formula. But their attempt to amend the legislation in 1973 backfired. Spectacularly.

The Department of Health, Education and Welfare was instead ordered to develop a framework for how Title IX was to be interpreted and followed, with most of the regulations addressing athletics. It was these rules, issued in 1975, that provided the backbone for the legislation and have allowed it to withstand repeated challenges in court.

"They could have gotten exemptions for the big sports ... if they didn't cry so much about it," said Donna Lopiano, who has been at the forefront of defending Title IX, first as the women's athletics director at Texas from 1975-92 and then as CEO of the Women's Sports Foundation from 1992 to 2007. "It created this media attention that allowed the women to voice the benefits of sport for boys and girls, and they convinced the public and Congress this was important for boys and girls. That was a tremendous accident."

Once given the chance, girls flocked to the playing fields.

Before Title IX, fewer than 300,000 high school girls - one in 27 - played sports; there were fewer than 32,000 female athletes at the collegiate level. By 1974, just two years after the passage of Title IX, the number of high schoolers participating in sports had skyrocketed to 1.3 million.

Now more than 3 million high school girls - one in two - play sports. More than 191,000 females played NCAA sports in 2010-11. And unlike their mothers or grandmothers, who were often limited to basketball and softball if they did get a chance to play, women are now participating in everything from squash to skiing, rugby to wrestling.

"Title IX was the second-most important piece of civil rights legislation passed in this country," said Debbie Yow, athletic director at North Carolina State. "Had it not passed, the options and opportunities for women in this country and the world would be vastly different."