Induction into the International Tennis Hall of Fame at Newport, Rhode Island, is the ultimate honor in tennis – it recognizes the sum of an individual’s achievements as being among the most important in the game’s history. While the champions of the sport normally grab the headlines – and rightly so – the Hall of Fame also maintains a Contributor category in order to pay tribute to those who make a transformative mark on the sport, off court. To date, five women have been acknowledged in this way:

Gladys Heldman: Class of 1979

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Gladys Heldman was the International Tennis Hall of Fame’s first female Contributor, and for good reason. She created the Virginia Slims Circuit, the precursor to the WTA. In 1953, as the mother of two young girls, Heldman founded World Tennis magazine. The venture started out as a one-woman show, but with the support of her husband, Julius, the supremely savvy Heldman grew her publication into one of the most influential forums in sports. Along the way, she advocated for equality and as the disparity in prize money offered to the genders grew, the leading women players turned to her for leadership. Heldman responded by rallying her business contacts to stage the Virginia Slims Invitational in Houston in September 1970, signing nine players to emblematic $1 contracts. The Original 9 faced the wrath of the establishment, but they were such a hit that Virginia Slims sponsored a full-blown calendar of events in 1971. Women’s professional tennis was on its way.

Mary Outerbridge: Class of 1981

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Time shrouds the details in mystery, but Mary Ewing Outerbridge is widely considered to be the "Mother of American Tennis." As a young woman, Outerbridge encountered the sport while on vacation in Bermuda in 1874 – the story goes that she saw British army officers playing the newly patented game of lawn tennis and they gave her a set of equipment to take home to New York. Once the racquets and net had cleared the scrutiny of suspicious customs officers, Outerbridge set up a hourglass-shaped court at the Staten Island Cricket and Baseball Club and played what may well have been the first tennis match in America against her sister, Laura. Even though a handful of men might also lay claim to bringing the sport to the United States, there’s no doubting Outerbridge ensured women would always have a place in the game. The U.S. National Championships were established in the 1880s, but Mary didn’t live to see how the sport would grow. She died in 1886 at the age of 34.

Peachy Kellmeyer: Class of 2011

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Peachy Kellmeyer goes down in history as the first employee of the Women’s Tennis Association (WTA). She was hired as the new body’s Tour Director in 1973. In the years that followed, Kellmeyer played a principal executive role, generating business growth and a regulatory structure for the tour, while never letting up in the battle for equal prize money. Before all that, the West Virginia native enjoyed a successful junior career and was the first woman to play on the men’s Division I tennis team at the University of Miami. But her commitment to women’s rights really shined through when, as Director of Physical Education at Marymount College in Florida, Kellmeyer fostered a landmark case that paved the way for Title IX; enacted in 1972, this legislation struck an important blow for gender equality in the U.S. education system by opening up athletic scholarships for women. Five decades on Kellmeyer continues to contribute to the WTA, which presents its annual Player Service Award in her honor.

Jane Brown Grimes: Class of 2014

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Hired in the 1970s to develop the scope and prestige of the International Tennis Hall of Fame – which meant everything from building the museum’s collection to overseeing the restoration of historic buildings at Newport – Jane Brown Grimes went on to hold myriad leadership and committee roles across the WTA, United States Tennis Association (USTA) and International Tennis Federation (ITF). Appointed managing director of the Women’s Professional Tennis Council (forerunner to the WTA Tour Board) in 1986, her achievements included negotiating the tricky move away from tobacco sponsorship and guiding the tour’s age eligibility rule into effect. As the second female President of the USTA, Brown Grimes oversaw important site developments at the Billie Jean King National Tennis Center and oversaw the USTA’s purchase of the Western & Southern Open at Cincinnati – boosting the concept of the U.S. Summer Series that fans enjoy today.

Nancy Jeffett: Class of 2015

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One of the first promoters of women’s professional tennis and a longtime chair of the U.S. Wightman Cup and Fed Cup competitions, Nancy Jeffett is also celebrated for her lifetime commitment to juniors and player development. She built a reputation for getting things done on the Texas tennis scene and Jeffett befriended Maureen “Little Mo” Connolly when the Grand Slam-winning great moved to Dallas after her playing career. In 1968, the duo co-founded the Maureen Connolly Brinker Tennis Foundation, and although Connolly died from cancer soon after, Jeffett spent the next four decades fostering young talent through individual and team competitions for girls and boys, right up to the international level. Meantime, in 1969, she staged the first Maureen Connolly Brinker Memorial Tournament, which later became a popular stop on the Virginia Slims Circuit and was the first women’s event to be televised in 1972.