[1] With the majority of major-league baseball players in the military during World War II, Phil Wrigley owner of the Chicago Cubs, established the AAGPBL in 1943 where it continued until 1954.

The first year the league played by softball rules, but that gradually changed until it was nearly identical with professional baseball.

Baker began her career with the South Bend Blue Sox in the league's first season and stayed with the team until 1950.

She was one of 68 Canadian players in the AAGPBL, while her sister, Genevieve George, also played in the league for the Kalamazoo Lassies.

When Baker joined the AAGPBL, she initially had promised her husband, who was fighting overseas in World War II, that she would quit the game when he returned.

During the 1950 season, Baker was traded to the Kalamazoo Lassies to act as a player-manager, becoming the only woman in league history to do so.