The church building and rectory were listed together on the National Register of Historic Places in 1980.

It was attended by 28 people in a building that doubled as a private home and a hotel owned by Fred Haberstroh.

St Mary's parish was established by Mazzuchelli in 1841, and he designed a small frame building that would serve as a church.

The cornerstone for the Greek Revival structure was laid on July 12, 1841, by Bishop Mathias Loras of Dubuque.

[4] When Hannon arrived in 1852, the foreign-born Catholic population in Iowa City was growing, especially the Germans and the Bohemians.

[5] In 1862 St. Francis Xavier Church was established for the pastoral care of Bohemian immigrants.

During his pastorate of 32 years saw the expansion of Catholic education and the building of the present church.

Hugh Gilles of Dubuque, Iowa and A. Groebel of Chicago were contracted to build the new church.

By the time it was dedicated the main altar, pews, pulpit, and stained glass windows were in place.

John F. Kempker and the following year the present rectory was built during the pastorate of Msgr.

The church renovation included removal of the communion rail, new carpet, reconciliation rooms, altar, ambo and chairs.

Kenneth Kunz, which included moving the baptismal font near the front door and new carpeting.

About the same time, the parish offices were moved out of the rectory to a house just east of the church.

The Romanesque Revival style is evoked by the use of the round arch for the entrance portals, the windows, and bell tower elements.

[6] The side elevations are seven bays in length and are divided by buttresses that are flanked by flat brick pilasters.

On the west side is a brick structure that covers a handicap entrance into the church itself.

The main facade is dominated by a two-stage, central bell tower that is capped by an octagon-shaped spire.

The three entrance portals are framed by compound round arches that feature limestone keystones and impost blocks.

The arches of the vaulted ceiling rise from impost blocks that are set high on the walls.

The small crucifix in the center is flanked by statues of angels holding grapes and wheat in reference to the elements of the Eucharist.

The Stations of the Cross are plaster bas-reliefs that were purchased by Father Emonds on one of his trips back to his native Germany.

There are large gabled wall dormers that end in shoulder parapets on the east and south elevations.

The porch features large semicircular brick arches that complement the church's Romanesque Revival style.

In 1844 Father Godfert started the parish's first school in the basement of the church with Miss Norma O'Connor as the first teacher.

In 1865 St. Joseph Institute, a school for advanced learning, was established by Father Emonds.

In 1975 the St. Mary's school buildings and convent were sold to the diocese for use by the Newman Center.

In the early 1990s, an addition was made to Regina High School and the elementary grades were moved from St. Patrick's.

[7] The Moline pipe organ (1883) is located in a gallery-level case at the back of the church.

It features a traditional style console with a keyboard cover that can be lifted to become the music rack and an attached keydesk en fenêtre.

The combination action is a fixed mechanical system and there is a flat straight pedalboard.