Question: What city , state is the US Catholic church that is the oldest extant example of secular Roman Catholic church architecture located ?

text: List of Catholic churches in the United States
Montana

This is a list of notable Catholic churches and cathedrals in the United States.
Church Dates Location City , State Description
St. Patrick 's Co-Cathedral 1904 built 215 N. 31st St. 45°46′52.08″N 108°30′41.23″W / 45.7811333°N 108.5114528°W / 45.7811333 ; -108.5114528 ( St. Patrick 's Co-Cathedral ( Billings , Montana ) ) Billings , Montana Gothic Revival
St. Wenceslaus Church built 2014 NRHP-listed 7724 Danvers Road 47°13′27.84″N 109°43′3″W / 47.2244000°N 109.71750°W / 47.2244000 ; -109.71750 ( St. Wenceslaus Catholic Church ( Danvers , Montana ) ) Danvers , Montana
St. John the Baptist Church built 1986 NRHP-listed Mullan Rd . 47°0′47″N 114°13′40″W / 47.01306°N 114.22778°W / 47.01306 ; -114.22778 Frenchtown , Montana
Sacred Heart Church 1926 built 1988 NRHP-listed 316 W. Benham 47°06′28″N 104°42′51″W / 47.10778°N 104.71417°W / 47.10778 ; -104.71417 ( Sacred Heart Church ( Glendive , Montana ) ) Glendive , Montana Romanesque Revival
St. Ann 's Cathedral 1889 built 1991 NRHP-listed 715 3rd Avenue North 47°30′31.32″N 111°17′43.44″W / 47.5087000°N 111.2954000°W / 47.5087000 ; -111.2954000 ( St. Ann 's Cathedral ( Great Falls , Montana ) ) Great Falls , Montana Gothic Revival
Cathedral of Saint Helena 1908 built 1980 NRHP-listed 530 N. Ewing St. 46°35′24.53″N 112°1′57.15″W / 46.5901472°N 112.0325417°W / 46.5901472 ; -112.0325417 ( Cathedral of Saint Helena ( Helena , Montana ) ) Helena , Montana Late Gothic Revival
St. Mary of the Assumption Church 1900 built 1980 NRHP-listed Off Montana Highway 287 45°21′15″N 112°06′26″W / 45.35417°N 112.10722°W / 45.35417 ; -112.10722 ( St. Mary of the Assumption Church ( Laurin , Montana ) ) Laurin , Montana Gothic Revival
St. Leo 's Church 1916 built 1985 NRHP-listed 124 W. Broadway 47°3′58″N 109°25′29″W / 47.06611°N 109.42472°W / 47.06611 ; -109.42472 ( St. Leo 's Catholic Church ( Lewiston , Montana ) ) Lewistown , Montana
St. Francis Xavier Church 1892 built 1982 NRHP-listed 420 W. Pine St. 46°52′28.21″N 113°59′52.88″W / 46.8745028°N 113.9980222°W / 46.8745028 ; -113.9980222 ( St. Francis Xavier Church ( Missoula , Montana ) ) Missoula , Montana Romanesque Revival
St. Joseph 's Church 1916 built 1999 NRHP-listed D'Aste Townsite 47°23′3″N 114°11′47″W / 47.38417°N 114.19639°W / 47.38417 ; -114.19639 ( St. Joseph 's Catholic Church ( Moiese , Montana ) ) Moiese , Montana
St. Ignatius Mission 1893 built 1973 NRHP-listed North Ave. 47°18′54″N 114°6′7″W / 47.31500°N 114.10194°W / 47.31500 ; -114.10194 ( St. Ignatius Mission ( St. Ignatius , Montana ) ) St. Ignatius , Montana Gothic Revival
St. Mary 's Mission 1866 built 1970 NRHP-listed North Ave. 46°30′29″N 114°5′43″W / 46.50806°N 114.09528°W / 46.50806 ; -114.09528 ( St. Mary 's Mission ( Stevensville , Montana ) ) Stevensville , Montana
St. Joseph 's Mission 1876 built 1998 NRHP-listed 3497 Montana Highway 284 46°24′32″N 111°26′55″W / 46.40889°N 111.44861°W / 46.40889 ; -111.44861 ( St. Joseph 's Catholic Mission Church ( Townsend , Montana ) ) Townsend , Montana Now the Canton Church Historic Site
St. Peter 's Church 1895 built 1990 NRHP-listed W. Orgain Ave 46°59′14″N 104°11′28″W / 46.98722°N 104.19111°W / 46.98722 ; -104.19111 ( St. Peter 's Catholic Church ( Wibaux , Montana ) ) Wibaux , Montana Gothic Revival