LONDON, England - July 4th wasn't just a big day for Americans in general this year, it was a big day for one American in particular - a WTA legend, too. Pam Shriver, a women's tennis legend in both singles and doubles, hit the big 5-0.

Shriver's playing career lasted almost two decades, from 1979 to 1997, and she amassed phenomenal numbers in both singles and doubles. Her singles highlights included one Grand Slam final (1978 US Open) and 21 WTA titles.

In doubles, Shriver won 21 Grand Slam titles (one with Natasha Zvereva and 20 with Martina Navratilova, the record for one partnership). Shriver spent a total of 48 weeks as the No.1 doubles player in the world. She also won Olympic gold in doubles at the 1988 Seoul Olympics (with Zina Garrison).

Shriver is now a member of ESPN's world-beating tennis commentary team.

From everyone at the WTA and wtatennis.com, Happy Birthday Pam!