[3] In 1971 it was rebranded as the Virginia Slims Circuit until 1978 and was a rival tour to the ILTF Women's International Grand Prix until 1976.

[7] King and eight other female tennis players – Americans Rosemary Casals, Nancy Richey, Peaches Bartkowicz, Kristy Pigeon, Valerie Ziegenfuss, and Julie Heldman;[8] and Australians Kerry Melville Reid and Judy Tegart Dalton – decided to enlist World Tennis magazine publisher Gladys Heldman to help negotiate for greater equality in prize money and provide valuable public relations assistance.

Gladys Heldman and the "Original 9" decided to target the Pacific Southwest Championships held in Los Angeles on the grounds that it paid eight times more money to men than it did to women.

Heldman attempted to get the tournament chairman, former professional tennis player Jack Kramer, to reduce the inequality between the prize money purses for men and women.

Heldman, with the assistance of Joe Cullman of Philip Morris, then offered US$5,000 out of her own pocket to allow the "Original 9" to sign token $1 contracts and set up their own tour of eight professional tournaments in 1970.