This presentation provides an historical sketch of the All-American Girls' Baseball League (AAGBBL). The League was created in 1942 as the All-American Girls' Softball League, by Philip K. Wrigley. He initiated the League as a non-profit organization governed by a board of three trustees. Mr. Wrigley's basic motivation for creating the AAGSBL was to organize substitute entertainment for men's professional baseball. In 1943, Mr. Wrigley began de-emphasizing the League's identity with softball and emphasizing its identity with baseball. The League was renamed the All-American Girls' Professional Ball League, but unofficially it was referred to as the AAGBBL. The League grew from its four original teams in 1943 to a maximum of ten teams in 1948. By 1954, it had dwindled down to five teams. The organizational structure of the League underwent three basic changes, all due to changes in administration. There were also both real and imagined problems with male managers and female players. To solve this, chaperones were hired. The League administrators maintained strict conduct rules for the players. The demise of the AAGBBL came after the 1954 season. Post-World War II social changes combined with intra-league changes to contribute to the League's demise. Many instructive lessons can be ascertained from the League's experience, however, for current and future application to women's professional sport. An appendix is attached which contains charts and tables on structure, salaries, and participants. (RC)