Date Founded: 1855
Church Location: 717 State St., Alton, Illinois
Notes: The current church was dedicated on October 28, 1855.
On January 9, 1857, the Episcopal See was transferred from Quincy to Alton. On May 15, 1859, Ss. Peter and Paul Church was consecrated as the Cathedral for the Diocese of Alton.
On October 26, 1923, the Episcopal See was trasferred from Alton to Springfield and St. Mary's in Springfield was designated as the new cathedral. The "old" cathedral's name was changed to Ss. Peter and Paul Roman Catholic Church.
Records Available in Diocesan Archives for Genealogy Research:
- Baptisms: 1852-1930
- Marriages: 1857-1930
- Deaths: 1857-1938