The original interior of cathedral was ornately decorated. Major renovations and additions made in 1915, 1936, and 1985 have altered its appearance. William Renwick designed the cathedral's original interior decorations, including three altars, doorway and arch decoration, metal ceiling, and frames for the Stations of the Cross. D. A. Bohlen and Son designed the original baptismal fonts and dark oak furnishings. In 1936 the original murals by Edgar S. Cameron of Chicago were covered with glass mosaics that depicted an enthroned Christ in Majesty flanked by Saints Peter and Paul. Bishop Chatard commissioned Cesare Aureli, a Roman sculptor, to carve the cathedral's Blessed Mother and Child statue and the Saint Joseph statue in white Carrara marble. They were installed around 1909. Aureli's statue of Saint Frances de Sales (Bishop Chatard's patron saint) was delivered in 1911 and installed on the high altar. A life-size Crucifixion was installed above the main altar in 1915. The sanctuary also includes a copy of Antonio Montauti's Pietà. Renovations begun in 1985 were based on liturgical changes made following the Second Vatican Council. The refurbished cathedral was rededicated on May 14, 1986.