The Archdiocese of Galveston-Houston says,
There has never been a cardinal appointed from a diocese south of the Mason-Dixon Line. Other than the Archdiocese of Los Angeles, this counrty’s cardinals have all been from archdiocese/dioceses in the northeast (e.g. New York, Baltimore, Washington, D.C., Boston, etc.) or the Midwest (e.g. Chicago, Detroit, St. Louis, etc.).
In fact, Los Angeles, Baltimore, Washington, DC, and St. Louis are all south of the Mason-Dixon Line.