I grew up as the youngest of five athletic girls. We ran and jumped and swam as much as possible when we were very young. Then, school began for the older siblings and their physical worlds contracted.

The oldest played high school softball for a season, but few of her friends played on the team and she soon looked to join other more sedentary clubs.

(Toni L. Sandys/The Washington Post)

The second and third sisters channeled their energies into cheerleading. They excelled at the kicks and flips, but their talents were kept, literally, on the sidelines.

By the time my energetic fourth sister entered school, opportunities for girls sports were opening up. Her friends were trying out for tennis and basketball. She saw older girls joining teams, winning scholarships. She saw a path ahead.

She was only about 10 years old when she asked my father to sign her up for a popular local road race. He later told me that he didn’t consider it a serious request. “It never occurred to me that she would really want to do that,” he said.

But something had changed in the previous few years that allowed my sister to consider, even insist upon, sports for herself.

When my dad didn’t follow through, she did it herself. She ran the race and won her age group. She beat out plenty of older runners, too.

That sister went on to run track for the next decade and was recruited by West Point to run for the military academy.

By the time I got to school, there was no question that I would play sports.

What changed between my older sisters’ time in school and that of their younger siblings was Title IX, the little law that turns 40 this Saturday.

“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,” reads the beginning of Title IX of the federal Education Amendments Act of 1972.

Shorthand for the full law is that it mandates that public schools provide equal opportunities for male and female students to participate in sports and compete for sports scholarships.

Few understood at the time (except, perhaps, its crafters) how profoundly Title IX would alter the cultural landscape. (This dynamic will be explored in a documentary, “Sporting Chance,” that ESPN2 plans to air this weekend.)

To understand how much things changed, we have to remember that 40, even 30 years ago, (it took a while for culture to catch up to the changes) sports were considered the domain of boys. A quick glance at any school playing field today makes that notion laughable.

According to the informative primer Fred Bowen provides today in KidsPost, “when Title IX was passed in 1972, only 295,000 girls competed in high school sports in the United States, compared with 3.67 million boys. During the 2010-11 school year, 3.2 million girls played high school sports, as did 4.5 million boys.”

The law is not without controversy, even now. Some college administrators, in particular, say it puts a hardship on their ability to support big-time men’s sports.

The benefits of the law, from my point of view as a child athlete and now mother of two budding female athletes, far exceed any downside.

School sports provide an unparalleled opportunity for physical and emotional growth as well as for friendship and character building. It seems obvious to afford both girls and boys the same access.

Like all major cultural progression, though, the obviousness of Title IX comes only in retrospect.

Happy Birthday Title IX. Wishes for many more.

What do you think of Title IX?

Has your family been affected by it?

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