TIMELINE: Serena Williams' journey to the top of the women's game
Serena Williams on Tuesday announced her retirement from the sport after this year's US Open starting on Aug. 29. The following is a timeline charting her rise to the top of the women's game:1999: Defeated Martina Hingis in the US Open final, becoming the first African American woman to win a Grand Slam singles title after Althea Gibson in 1958.