Its building initiated by Abp. John Ireland, the new church of St. Mary was to serve Immaculate Conception parish, the first Catholic community west of the Mississippi River (excluding the missions of the Southwest). It was the first American church made a basilica, February 1, 1926, by Pope Pius XI.*
* Some make the same claim for St. Adalbert's Basilica in Buffalo, NY. After investigating the question, CHn concluded that St. Mary's is the more accurate claim. The following passage contains the relevant information (excerpt from an article by St. Mary archivist Heather Craig, reprinted with permission):
This Spring, Docents leader Brian Dusek forwarded me an interesting
query from a fellow docent. How, she wondered, could we proclaim
ourselves the first Basilica in the United States when several
contradictory web sites gave that honor to St. Adalbert's in Buffalo,
I checked her sources, and indeed, a website maintained by the
Polish Genealogical Society of New York, as well as an excellent
resource site by the Canadian Catholic iEnchiridion
(www.ca-catholics.net), listed St. Adalbert's date as 1907. If true, we
had missed the title by a significant period of time. Yet how could the
esteemed Father Reardon have been misled, dedicated historian that he
was? And how could the Basilica of Our Lady of Victory in Lackawanna,
New York, be similarly misled, proudly promoting themselves as the
second Basilica in the United States (elevated July 20, 1926, only a few
months after us)?
My search led me to Sister Ann Louise, Archivist for the Diocese
of Buffalo, as both St. Adalbert's and Our Lady of Victory are within
that Diocese. She confirmed our status, and provided me with citations
for several outside resources. The most definite proof of our claim is
an article by Rev. Robert McNamara, "Minor Basilicas in the United
States," published in the July, 1959 issue of the Homiletic & Pastoral
Review. In his article, he lists only twelve minor basilicas in
existence in the United States. Our "competitor" receives mention as a
"At times the title of Basilica has been applied to other American
churches in addition to the twelve we list. If they merit the title, the
papal document conferring the rank has at least never been published in
the Acta Apostolicae Sedis. More likely their claim has been based on
their obtaining indulgence-affiliation with one of the major basilicas.
This is the case with . . . St. Adalbert, Buffalo, affiliated with St.
Peter's. As we have already pointed out, affiliation does not confer the
rank or prerogatives of a minor basilica".
According to the translation of the document "designating St. Adalbert's
Church a Basilica" sent to me by that church, St. Adalbert's was so
affiliated in 1907. This document grants Apostolic indulgences and
privileges in accordance with affiliation. However, it does not confer
the "singular title and dignity of a Minor Basilica", which our own
papal bull does so clearly.