The oldest standing church in Chicago was built of yellow Milwaukee brick in the 1850s. It survived the Great Chicago Fire of 1871 to become the city's main Irish parish. The two spires were added in 1885. They are different from each other to symbolize the Eastern and Western church. From 1912-1922, Thomas O'Shaughnessy remade the interior in the Celtic-Revival style. This included the addition of elaborate interlaced stenciling and stained-glass windows—one of which contains more than 250,000 pieces of glass. Both of these design features were inspired by the Book of Kells.