Coco Gauff wins US Open for her 1st Grand Slam title at age 19

Gauff, who is from Florida, is the first American teenager to win the country's major tennis tournament since Serena Williams in 1999. If last year's U.S. Open was all about saying goodbye to Williams as she competed for the final time, this year's two weeks in New York turned into a "Welcome to the big time!" for Gauff.