There was a rousing tribute at the U.S. Open in New York last night for the tennis legend that leveled the playing field.

Former U.S. first lady Michelle Obama led the accolades as Billie Jean King celebrated the 50th anniversary of the U.S. Open becoming the first sporting event to offer equal prize money to men and women competitors.

The now 79 year old tennis legend was the defending U.S. Open champions in 1973 when she rallied her fellow women players not to play in that year’s tournament unless women were given the same pay as men.

That year, the champions of both the women’s and men’s draw each made $25,000.