One of the characters in Kate Quinn's The Briar Club played in the All-American Girls Professional Baseball League (AAGPBL), which existed from 1943 to 1954.
In 1942, owners of professional baseball teams and stadiums were in a panic. Young men who played ball were being drafted to fight in World War II, and several minor league teams had collapsed as a result. Concerned that even the major leagues would be impacted, Chicago Cubs owner Philip K. Wrigley (of chewing gum fame) formed a committee to brainstorm possible solutions to this potential lack of players. The committee recommended forming a women's softball league to fill the void, and the All-American Girls Softball League was born.
The committee faced some questions and issues right off the bat (pun intended), one of which was how to structure the game. They decided to keep the larger ball and underhand pitching style of softball, but moved the bases out to allow more hits and fielding opportunities, in theory ...