The Diocese of Joliet was formed in 1948 from what had been a part of the Archdiocese of Chicago. The Diocese of Joliet consists of Dupage, Ford, Grundy, Iroquois, Kankakee, Kendall, and Will Counties in Illinois. There were four Polish parishes in this region. St. Stanislaus B&M Church in Kanakakee was founded in 1901 but was closed in about 1998. St. Thaddeus Church in Joliet was founded in 1928 but was closed in 2005. Its school was located at 510 Columbia Street. It is not certain if this was a combination school/church complex or if the church building might have been across the street but sold to another denomination. The map provided plots the locations of Polish Roman Catholic Churches in the Diocese of Joliet, Illinois. Given addresses were usually of the rectory and not the church building itself.