Wilma RudolphTrack and Field 1 of 8
Known as "The Tornado," Wilma Rudolph made a name for herself at the 1960 Olympics, where she became the first American woman to win three gold medals in track and field. Even more remarkable is what she overcame to get there, specifically a nasty battle with polio that left her leg twisted and in a brace for many years.
Nothing could stop Rudolph though, who joined the U.S. Olympic track and field team when she was only 16. Because of her victory in the 1960 Games, she brought widespread attention to women's track both in the U.S. and internationally.
Janet GuthrieAuto Racing 2 of 8
Janet Guthrie is the first-ever woman to qualify and compete in the Indianapolis 500 and Daytona 500. Though she initially began her professional life as a flight instructor and aerospace engineer, she soon took up an interest in motorsports and dedicated herself to it full-time by 1972.
Her big break came in 1977, when she competed at both Indianapolis and Daytona. Not only did she break the gender barrier, but in the Daytona 500, she was also named top rookie.
The progress she made on behalf of female racers earned her one of the first spots in the International Women's Sports Hall of Fame.
Billie Jean King3 of 8
Before Venus and Serena, there was Billie Jean King, a professional tennis player who famously won the 1973 "Battle of the Sexes" against Bobby Riggs. One of the most famous and watched tennis events of all time, the match legitimized women's tennis after King defeated Riggs, who was vocal about his sexist beliefs leading up to the event.
During her career, King went on to win 39 Grand Slam titles and became the top ranked female tennis player in the world. She was inducted into the International Tennis Hall of Fame in 1987 and into the National Women's Hall of Fame in 1990. She also founded the Women's Sports Foundation, which is committed to helping girls and women get involved in sports.
Ann Meyers DrysdaleBasketball 4 of 8
Ann Meyers Drysdale's groundbreaking basketball career began early—she joined the U.S. national team while she was still in high school in 1974, the first athlete to ever do so. She followed up that impressive feat by becoming the first woman to ever sign a four-year athletic scholarship with UCLA, but she wasn't finished yet.
Drysdale is perhaps most famous for being the first woman to sign a contract with an NBA team, the Indiana Pacers, in 1979. Although she was not chosen for the final squad, the move signified that women could play the sport professionally years before the founding of the WNBA.
Tracy CaulkinsSwimming 5 of 8
Tracy Caulkins is a three-time Olympic gold medalist and one of the most diverse swimmers to ever enter the pool. She is known for her versatility, specifically being able to master and compete in all four competitive swimming strokes: the butterfly, breaststroke, backstroke and freestyle.
What's even more notable about Caulkins is that many consider her the best swimmer in the history of the sport, male or female. By the time she retired in 1984, she had set five world records and 63 U.S. records, more than any other American swimmer, male or female.
Kathryn SmithFootball 6 of 8
Football has always been among the hardest sports for women to break into, but Kathryn Smith recently made huge strides after she was hired as the Buffalo Bills Special Teams Quality Control Coach, making her the first full-time female coach in NFL history.
Smith is part of an influx of women joining the coaching ranks of major professional sports in recent years.
Mo'ne DavisBaseball 7 of 8
The youngest pioneer on our list, Mo'ne Davis made history in 2014 when she became the first girl to ever pitch a winning game in the Little League World Series. That isn't her only accomplishment, though. She was one of only two girls to play that year and the first African-American girl to play in the Series as a whole.
Davis went on to appear on the cover of Sports Illustrated (another first), was praised by First Lady Michelle Obama and named one of "The 25 Most Influential Teens of 2014" by Time magazine.