Dubuque architect Fridolin Heer designed the chapel built in the back the cathedral in 1882. The new building obscured the three stained glass windows above the altar, so they were removed and placed above the altar of the new chapel. It served for nearly a century as the Blessed Sacrament Chapel, and its interior was briefly seen in the movie F.I.S.T. (1978). A number of other renovations were begun in 1886 according to the designs of Chicago architect J.J. Egan. They included new vaulting made of iron and lowering the column's capitals down by . The interior was replastered, new stations of the cross were imported from Germany, a new gallery was installed in the rear of the church, and a large arch was cut into the tower to allow light from the lancet window to brighten what once was a dark nave. The frescos in the church were completed at this time by Luigi Gregori, artist in residence and professor at the University of Notre Dame who had previously worked at the Vatican, and his son Constantine. Bishop John Hennessy rededicated the cathedral on November 21, 1886. New stained glass windows, whose openings in the nave had been lowered , were imported from London and installed in 1889.