In the 1950s, an 11-year-old girl wasn’t allowed in a tennis tournament group photo, simply because she wasn't wearing a tennis skirt. That little girl was Billie Jean King.

BJK didn’t let the photo snafu stop her from changing the game for female athletes. During her storied tennis career, she became a top-ranked women's tennis player (she reached the number one spot in 1966) and won a casual 39 (!) Grand Slam titles. And she dedicated much of her time and energy on and off the court to fight for equality.

Here, just a handful of Billie Jean King's many accomplishments:

●︎ She became the first president of the Women’s Tennis Association

●︎ She lobbied for equal prize money

●︎ She started the Women’s Sports Foundation

●︎ She was the first woman to have a major sporting venue named after her—the USTA Billie Jean King National Tennis Center in New York

●︎ She was one of the first female athletes to openly embrace her homosexuality, and she became a champion for LGBTQ rights

●︎ She started a non-profit, the Billie Jean King Leadership Initiative, which advocates for more diversity and inclusivity in the workplace One of BJK's other career accomplishments: At the age of 29, she took on 55-year-old male tennis player Bobby Riggs, another former number-one ranked tennis player. Their 1973 match was called the "Battle of the Sexes." That match is now getting the Hollywood treatment in Battle of the Sexes, a movie starring Emma Stone (who plays BJK) and Steve Carell (who plays Riggs). ## The "Battle of the Sexes" match was more than a typical competition—it was all about gender equality. Some of Riggs sexist taunts before the match: "Women belong in the bedroom and kitchen, in that order.” And also: "Women play about 25 percent as good as men, so they should get about 25 percent of the money men get." Let's just say BJK rose to the occassion when she faced Riggs on the court—a major victory for women. “This match was about social change,” King, now age 73, recently told Yahoo! Sports. “I knew what it meant because I was on tour, playing, and people would come up to me as I traveled the country. I’d listen to them. Some were angry. Some were saying, ‘Come on, you’ve got to win.’ Some were saying, ‘Why the hell are you doing this?’”

“[#EmmaStone] embodies King’s tenacity and turmoil with heart and intensity. Most importantly, though, it’s a long overdue testament to a dedicated athlete and champion of women’s rights.” 📸: @vanityfair #BattleoftheSexes

A post shared by #BattleoftheSexes (@battleofthesexesmovie) on Sep 5, 2017 at 1:23pm PDT

Even if you're not a tennis player, an athlete, or a member of the LGBTQ community, BJK's words of wisdom can resonate with anyone trying to figure out the struggles of life. To help prep for the movie, here are some of her most famous quotes. ## Let BJK's words inspire you to kick ass, believe in yourself, and defy the odds: 1. On making a difference:
> “Ever since that day when I was 11 years old, and I wasn't allowed in a photo because I wasn't wearing a tennis skirt, I knew that I wanted to change the sport.” > — Billie Jean King 2. On persevering:
> “Champions keep playing until they get it right.” > — Billie Jean King 3. On owning your mistakes:
> “Be bold. If you're going to make an error, make a doozy, and don't be afraid to hit the ball." > — Billie Jean King 4. On diversity:
> “It's just really important that we start celebrating our differences. Let's start tolerating first, but then we need to celebrate our differences.” > — Billie Jean King 5. On changing the game:
> “I wanted to use sports for social change.” > — Billie Jean King 6. On character:
> “Reputation is what others think about you. What's far more important is character, because that is what you think about yourself.” > — Billie Jean King 7. On hard work:
> “Natural talent only determines the limits of your athletic potential. It's dedication and a willingness to discipline your life that makes you great.” > — Billie Jean King 8. On self-awareness:
> "The most important words that have helped me in life, when things have gone right or when things have gone wrong, are 'accept responsibility.'" > — Billie Jean King 9. On authenticity:
> “Don't let anyone define you. You define yourself.” > — Billie Jean King 10. On self-care:
> “My whole life has been about equal rights and opportunities. For me it really goes back to the health of mind, body and soul.” > — Billie Jean King 11. On pressure:
> "Pressure is a privilege—it only comes to those who earn it." > — Billie Jean King --- Read next: The Secret to Successfully Planning Long-Term Goals