Complex sentence: The original see was canonically erected by Pope Pius IX on July 19,1850 as the Diocese of Saint Paul of Minnesota, a suffragan episcopal see of the Archdiocese of Saint Louis.
Split into simpler sentences: The original see was canonically erected by Pope Pius IX on July 19,1850 as the Diocese of Saint Paul of Minnesota. The Diocese was originally erected as a suffragan see of the Archdiocese of Saint Louis.