Watch: Rosie Casals talks about growing women's tennis

"We had nine individual women who thought the same way. None of us felt that we shouldn't do what we were doing ... striving for more than what we had. I don't even think we thought that we were going to fail. We were so tuned in to the fact that this was the right thing to do."

Rosie Casals was always the rebel. From her diminuative stature to her upbringing on public tennis courts, the San Franciscan-born daughts of Salvadorian immigrants joined the women's tennis tour with something to prove, and that attitude served her well in her role as a member of the game-changing "Original 9." Casals and eight others—Peaches Bartkowicz, Julie Heldman, Billie Jean King, Kristy Pigeon, Nancy Richey, Valerie Ziegenfuss, Judy Tegart Dalton and Kerry Melville Reid—changed the course of tennis in 1970, when they signed symbolic $1 contracts to break away from the sport's governing bodies and form their own tour, the Virginia Slims Circuit, as a precursor to the modern-day WTA tour. 

Last summer, Casals and the rest of the Original 9 became the first group inducted into the International Tennis Hall of Fame in Newport, R.I. and the group was honored at the US Open to celebrate a half-century since their watershed moment. Casals recently joined Courtside, the official podcast of the US Open, to talk about shaping women's tennis and the progress towards gender equity that she sees in sports overall today. 

Watch a clip from the interview in the video below and to listen to Courtside: The US Open Podcast in full, visit usopen.org/podcast.