St. Augustine Church has stood on New Diggings Hill since its construction in 1844-47 as a place of worship for Irish mining families of the vicinity. Striking in its classical simplicity, the little 30x50 frame church is a beautiful example of Greco-Gothic Revival architecture. It was designed and constructed by Father Samuel Mazzuchelli OP (1806-1864), who served as an itinerant missionary, pastor, and builder in the tri-state area during his ministry in the American Midwest from 1835 to 1864. Its exterior is plank siding, scored and painted to resemble large blocks of limestone, and its interior has hand-hewn pews, a carved altar, and sanctuary carpeting that reproduces the original. The Meneely bell in the tower was brought from the Meneely foundry in West Troy, New York, and installed in 1847. Below the church is a small school room where a Dominican sister from Sinsinawa taught 60 pupils in the late 1840's. The building is listed on the National Register of Historic Places, and the Father Samuel Mazzuchelli Assembly, Knights of Columbus, provided for a historical restoration of the church to its original beauty in 2007.