The American Association was founded in October 2005 by four former Northern League teams; these teams were joined by five teams from the Central Baseball League and by an expansion team in St. Joseph, Missouri.
The American Association was founded in October 2005 when Northern League teams left that league. Following the folding of the Central Baseball League, five teams from that league joined with the four former Northern League franchises, and to even things out an expansion team was placed in St. Joseph, Missouri.