Named one of the 100 Most Important Americans of the 20th Century by Life Magazine, Billie Jean King has long been a champion for social change and equality. Her many accomplishments include winning 39 Grand Slam singles, doubles, and mixed doubles, founding the Women's Tennis Association and co-founding World Team Tennis. There are few people who have done more for the game of tennis than Billie Jean King, who was awarded the Presidential Medal of Freedom and honored with the naming of the USTA Billie Jean King National Tennis Center at the US Open.