NEW YORK, July 31, 2017 /PRNewswire/ -- Citizen is pleased to announce its partnership with Billie Jean King, former number world number one professional tennis player, who is well known for her advocacies for gender equality and social justice. A 2009 recipient of the Presidential Medal of Freedom and named one of the "100 Most Important Americans of the 20th Century" by Life Magazine, Billie Jean King represents the many values of Citizen watches in time for the brand's 25th Anniversary as the Official Timekeeper of the U.S. Open Tennis Championships.