Although the Diocese of Natchez was established in 1837 by Pope Gregory XVI, the first bishop, Thomas Heyden of Pittsburgh, declined the appointment. The new diocese embraced 47,000 square miles, encompassing the entire state of Mississippi. There was not one Catholic Church or resident priest. The last resident priest in Natchez was withdrawn in 1798 with the end of Spanish rule. It was not until 1841 that a Sulpician Father, John Joseph Chanche of Baltimore, accepted the appointment as the first Bishop.