Construction of the Classical Renaissance style Cathedral began in 1906, with the first services held there in 1915. It was designed by French architect Emmanuel Masqueray, chief designer of the 1904 World's Fair in St. Louis.
Exterior walls are of Rockville granite from St. Cloud, Minnesota. Interior walls are American Travertine from Mankato, Minnesota. Many different kinds of imported marble were used in columns and in chapels surrounding the sanctuary. Six chapels are dedicated to the patron saints of the ethnic groups that settled the area: St. Anthony for the Italians; St. John the Baptist for the French Canadians; St. Patrick for the Irish; St. Boniface for the Germans; Saints Cyril and Methodius for the Slavs; and St. Therese of Lisieux for the missionaries.
Large statues of the four evangelists may be found in the niches of the four main piers of the church. The rose windows and the other smaller windows were designed by Charles Connick. Also the bronze baldachin, and massive bronze Te Deum and Magnificat grilles which honor the life of St. Paul. There are many inscriptions carved in the stone on the interior walls and on the facade of the front of the Cathedral. Added to the church in 1987 were five large bronze bells cast in France. They replaced the original single bell, "which was not loud enough to scare a pigeon," according to former Cathedral rector, Msgr. Ambrose Hayden.
