Billie Jean King has been nominated for a Congressional Gold Medal, the highest civilian award in the United States, fifty years after the Battle of the Sexes and the introduction of equal pay at the US Open.

Former World No. 1 King has had a profound impact on the sport. The now 79-year-old had a hugely successful career on the court, winning 39 Grand Slam titles across singles and doubles, and was inducted into the International Tennis Hall of Fame in 1987.

However, she also had a major positive impact on a social level, fighting for gender equality in the sport and in society as a whole.

This year marked the fiftieth anniversary of equal prize money being offered at the US Open. King met with the tournament organizer the year before after she earned significantly less than her male counterpart for winning the Slam.

She ensured a sponsorship deal with the deodorant brand Ban and threatened to boycott the event the following year if equal pay was not given to women players. Following this, the other Grand Slams followed suit across the next three decades. At this year's New York major, the women's singles champion Coco Gauff thanked King for fighting for equal prize money as she received her $3 million paycheck.

Moreover, September 20 made it 50 years since the historic Battle of the Sexes between King and Bobby Riggs. The 55-year-old Riggs was sure that he could still beat any top-ranked female tennis player, but King clearly proved him wrong. The match was a huge spectacle watched by people across the nation, with King's straight-sets victory changing the way that many women perceived themselves and their capabilities.

Now, King has been nominated for the Congressional Gold Medal by senators Kirsten Gillibrand (New York), Kyrsten Sinema (Arizona), and Shelley Moore Capito (West Virginia). If the bill goes through, King will be the first individual female athlete to receive the honor.

In 2009, King was awarded the nation's other highest civilian award, the Presidential Medal of Freedom, due to her work in elevating others through her sport.