the diocese of peoria was canonically erected on february 12, 1875. its territory was taken from the former diocese of chicago. the first bishop of the diocese was john lancaster spalding. later bishops included william e. cousins (bishop from 1952 to 1958), john baptist franz, edward william o'rourke, and then o'rourke's coadjutor bishop and later successor, john j. myers (now archbishop emeritus of newark), who hosted saint mother theresa of calcutta's december 1995 visit to the peoria diocese.