The All-American Girls Professional Baseball League (AAGPBL) was a women's professional baseball league founded by Philip K. Wrigley which existed from 1943 to 1954. The AAGPBL is the forerunner of women's professional league sports in the United States. Over 600 women played in the league. In 1948, league attendance peaked at over 900,000 spectators. The most successful team, the Rockford Peaches, won a league-best four championships. The 1992 motion picture A League of Their Own is a mostly fictionalized account of the early days of the league and its stars.

Is it true that was there ever a women's baseball league?
yes