Before tennis icons Serena Williams and Coco Gauff took the world by storm, there was Althea Gibson.Gibson cemented herself in history as the first African American to cross the color line to play and win Wimbledon and the U.S. Nationals in 1957. By the end of 1957, she was ranked the number one player in the world.Achieving her accomplishments was no easy feat, and seems even more impossible to accomplish when considering the era she was competing in. During the 1940s and 1950s, tennis was extremely segregated. To qualify for the U.S. Nationals, now called the U.S. Open, Gibson had to compete in major tournaments held by the U.S. Lawn Tennis Association. The hurdle was that these tournaments historically only invited white tennis players. It wasn’t until 1950 that she was invited to play at the Eastern Lawn Tennis Association Grass Court Championships in New Jersey. It took a few years to gain her stride among new competitors, but in 1956, she became the first black person to win the French Championships. The next year, she won Wimbledon at age 29. Despite the obstacles she faced on and off the court, Gibson continued to win championships. Watch the video above to discover more fascinating details on Althea Gibson's life.