The spire on the eastern side of the church is over 200 feet tall and it has four large clocks installed.
In 1879, Bishop John Hennessy of Dubuque realized that Saint Mary's Church – which was the main German parish for Dubuque – would no longer be enough to serve all the German immigrants in the city as their population continued to grow.
A large number of young German families came to the area in search of jobs at the shops and other employers.
With the availability of electricity, in 1922 a new large Wangerin-Werchardt pipe organ was installed in the church.
In the years following World War II, the parish school had the largest student population in the midwest.
However, over time the school population declined as more families moved to the western parts of the city.
This was because of a small group of administrators whose main objective was to push out the lower income families in the north end.
Early photos of the church show two additional stained glass windows in the sanctuary behind the main altar.
On the western side, images of a number of important historical events worldwide are displayed - such as the signing of the Declaration of Independence.
[citation needed] The church ceiling features paintings by Clotilde Elizabeth Brielmaier.
In the 1990s, a new handicap accessible entrance was built on the western side of the church, which included an elevator.
Previously handicapped parishioners were encouraged to park on the east side of the church, where a street-level entrance was available.
This was after a cross burning was done by a gang of young racists in the city to intimidate African-American people living in Dubuque.