This year marks the 50th anniversary of TENNIS Magazine's founding in 1965. To commemorate the occasion, we'll look back each Thursday at one of the 50 moments that have defined the last half-century in our sport.

In 1973, the U.S. Open became the first of the Grand Slams to dole out equal prize money to men and women. It took some pressure from Billie Jean King and her nascent Women’s Tennis Association, as well as a sizable cash supplement from the Ban Deodorant company, but the tournament came up with a $25,000 purse for each draw. it was, by today’s standards, a bargain.

One month before the Battle of the Sexes was played in Houston, equality between male and female athletes had taken a significant step forward. To many, it was also an unthinkable step. Looking back at the early ’70s, Rod Laver, who is no one’s idea of a raging male egomaniac, admitted that, “I was astounded by the money that poured into [the women’s] side of the game. Billie Jean made $117,000 in 1971 and $113,200 in 1972. Did I think I’d live long enough to be out-earned by a woman in my line of work? It would have been too preposterous to even think about.”

If even the mild-mannered Rocket felt that way, maybe it’s understandable that it took the rest of the sport a little while to come around to the idea of equal pay. Thirty-four years, to be exact: In 2007, Wimbledon finally joined the 20th century and became the fourth of the four majors to level their paying field.

Over the years, in defense of inequality, Wimbledon had cited the fact that the men drew bigger TV audiences in the U.K., and played best three-of-five sets instead of two-of-three, as the women did. But in 2007, the All England Club gave up its rear-guard action; by that point, the difference in prize money was small enough that it only qualified as a symbolic gesture. So Wimbledon made a long-overdue gesture in the opposite direction.

“The time is right to bring this subject to a logical conclusion and eliminate the difference,” said All England Club chairman Tim Phillips in announcing the policy change. “We believe our decision to offer equal prize money provides a boost for the game as a whole and recognizes the enormous contribution that women players make to the game and to Wimbledon.”

From King in the ’70s to Venus Williams in the first decade of this century, generations of women players had been instrumental in defying the widespread and deeply rooted skepticism on this subject. King had participated in the Battle of the Sexes not just to show that women could compete with men, but that they were skilled athletes who, like men, deserved to be paid for their efforts. Watching Venus win Wimbledon thirty years later, no one would have dared to deny that fact anymore.

“The greatest tennis tournament in the world has reached an even greater height today,” Venus said in 2007. “I applaud today’s decision by Wimbledon, which recognizes the value of women’s tennis.”

Yet that value is still not recognized by all, and the prejudice against equal pay is a persistent one. In 2012, members of the ATP player council began making skeptical noises about it again. But as Phillips said, for Wimbledon and the rest of the majors, it’s only logical. The tournament wouldn’t be what it is, a de facto world championship and mid-summer celebration of the sport, without both genders bounding around on the grass. When we think of the event’s history, we think of Bjorn Borg, Pete Sampras, and Roger Federer, but we also think of Chris Evert, Steffi Graf, and Serena Williams. Who now would say that those women aren’t worth just as much to the tournament, and the game, as the men?