Written By: Eliza Berman

When Philip K. Wrigley spearheaded the effort to remedy professional baseball’s wartime decline with a women’s league, one question dogged the league’s founders: what, exactly, to call it. It wasn’t technically softball. The ball was smaller, the bases farther apart and stealing bases forbidden in softball was permitted. But it wasn’t baseball, either: the ball was larger and the bases, closer. They settled on a compromise: The All-American Girls Professional Ball League.

The league that would later inspire the 1992 movie A League of Their Own and the enduring exclamation, “There’s no crying in baseball!” had just kicked off its third season when LIFE featured it in a photo essay in 1945. The six teams, all based in the Midwest, were comprised of nearly 100 women between the ages of 16 and 27 who played for $50 to $85 per week. Eight were married and three had children. Nearly half a million spectators were expected to turn out over the course of that season, shelling out $0.74 for a seat to watch the Rockford Peaches face the South Bend Blue Sox and the Grand Rapid Chicks take on the Racine Belles.

As exciting as it was to watch women slide and steal and scuff their knees, the league was a product of its time, and its strict rules of conduct reflected this. As LIFE reported in its story, “League rules establish she must always wear feminine attire, cannot smoke or drink in public, cannot have dates except with “old friends” and then only with the approval of the ever-present team chaperone.”

But as demure as the players may have been off the field, they were serious athletes as soon as the first pitch was thrown. Blue Sox Catcher Mary “Bonnie” Baker could throw 345 feet. Lefty pitcher Annabelle Lee threw a perfect game. And Sophie Kurys stole 1,114 bases during her ten-year career. The appeal of players” athleticism kept the league going for more than a decade, with attendance peaking in the late 1940s at 910,000 fans. But the league’s decentralization, a dearth of qualified players and the rise of televised major league games eventually led to its demise, with players retiring their gloves after the close of the 1954 season.

Liz Ronk, who edited this gallery, is the Photo Editor for LIFE.com. Follow her on Twitter at @LizabethRonk.

Catcher May “Bonnie” Baker of the South Bend Blue Sox, 1945; she had five brothers, four sisters, all of them catchers on Canadian ball teams.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Pitcher Carolyn Morris of Rockford Peaches, 1945.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Outfielder Faye Dancer, Fort Wayne Daisies, All-American Girls Professional Baseball League, 1945. She served as an adviser for the 1992 movie A League of Their Own and was a model for Geena Davis’ character.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Pitcher Annabelle Lee, Fort Wayne Daisies southpaw, of the All-American Girls Professional Baseball League. Her nephew, Bill Lee of Major League Baseball, credited her with teaching him how to pitch.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Girl's Midwest baseball league, 1945.

The All-American Girls Professional Bsaeball League, 1945

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Girl's Midwest baseball league, 1945.

The All-American Girls Professional Baseball League, 1945.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Girl's Midwest baseball league, 1945.

The All-American Girls Professional Baseball League, 1945.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Anastasia Batikis, a Racine Belles’ outfielder, in action in the All-American Girls Professional Baseball Laegue, 1945.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Penny O’Brian, Fort Wayne Daisies rookie infielder in the All-American Girls Professional Baseball League, 1945.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Faye Dancer of the Fort Wayne Daisies paid the price for sliding while wearing a league-mandated skirt in the All-American Girls Professional Baseball League, 1945.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Gear from the All-American Girls Professional Baseball League, 1945.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

Members from all six teams in the All-American Girls Professional Baseball League posed for a group portrait, 1945.

Wallace Kirkland The LIFE Picture Collection/Shutterstock

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