The tradition of Ladies Day at Wrigley Field actually began before it was called "Wrigley Field." The man who built the park, entrepreneur Charlie Weeghman, actively pursued a female audience for the team that played there the first two years of the ballpark's existence: The Chicago Whales.
The National League had a rule banning "Ladies Day" at the time, and Weeghman took advantage of that rule to differentiate his product from the Cubs. He immediately instituted Ladies Day every Friday, and women came in droves.
After lobbying from the Cubs, the NL finally saw the error of it's ways. By then the Cubs were playing at Wrigley Field, and they rode that tradition to some of their biggest crowds in history.
They also created a lifetime of memories. Arizona Central recently asked their readers to send in some of their favorite Wrigley memories, and many of them specifically mentioned the wonderful tradition of Ladies Day.
George Matthews wrote...
"Almost 60 years ago, I became a Cubs fan began on Ladies Day at Wrigley Field. This has always been a fond memory for me. That day was always the day my Grandma would take me to the first Cubs game of the year. A huge fan, she would somehow endure two connecting bus rides plus a ride on the "L" hauling her 7-year-old grandson (me) behind. I was transformed into a lifelong Cubs fan because of Ladies Day and Grandma."
Andrea Smith wrote with a similar experience...
"In the early '40s I attended a girls Catholic high school close to Wrigley Field. In the spring the sisters would either dismiss us early or turn their heads when we skipped out to go to the ballgame. Hooray for the sisters. In the '30s my aunts from the west side would ask me to come to Ladies Day. I would put on high-heel shoes (and socks) thinking I would look old enough to get in. I always did."
Shirley Barone also remembered it...
"We took the "L" directly to Wrigley Field. My Mom and her sister went to the games on Ladies Day, and all they had to pay was the tax, and in that day (the '40s) the cost was 25 cents. I remember sitting on her lap during the game."
By the 1960s, it had changed slightly. Actor Joe Mantegna wrote about Ladies day this way (in the New York Times) on the eve of the first Wrigley Field night game...
"Friday was Ladies' Day. Once you reached puberty, Friday at Wrigley was paradise. Hordes of halter-tops and bikinis, coming more to tan and wave at cute outfielders than get involved in a ballgame, but if you were a teen-aged boy, who cared!"
The tradition ended in the 1970s, but the memories, and the ladies, will always remain.